add zeroconf support based on qt4 libraries (#667)

* Removed -HUP so the default -TERM signal is sent instead.
- hyperiond only listens for TERM and INT. HUP is often used to get an exe to reread its config

Changed pgrep to add '-x' so it wont partial match on the exe name.
- I have multiple instances with multiple hyperiond-instance1 names
- this ensures the service script only kills the right process

* reversing errant change to hyperion.systemd.sh

* added bonjour/zeroconf service discovery to the json interface.

When clients are also modified, they can
- find hyperiond on the network much more quickly than ping/portscan;
- find multiple instances running on different ports instead of assuming 19444

* Moved zeroconf calls to hyperiond.cpp

* Added mDNS/zerconf/bonjour registration for proto server

Added config options.
        "jsonServer" :
        {
                "port" : 49444,
//              "mDNSDescr" : "hyperiond jsonServer blah de blah",
                "mDNSService" : "_hyperiond_json._tcp"
        },

* cleaned up a couple of compiler warnings

* moved bitpair_to_byte initialiser to (hopefully) work with older GCC

* compiler warning in udp driver
removed some tabs in ws2812b.cpp

* formatting - spaces to tabs

* moved rpi_281x to tag sk6812-v1.0

* moving to my fork of rpi_281x

* Now uses the led device name and hostname to create the annouce name


Former-commit-id: abfa51bcf359cafa63338181c1b83ecfd231bc87

include/bonjour/bonjourrecord.h

@@ -0,0 +1,60 @@
+/*
+Copyright (c) 2007, Trenton Schulz
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice,
+    this list of conditions and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ 3. The name of the author may not be used to endorse or promote products
+    derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef BONJOURRECORD_H
+#define BONJOURRECORD_H
+
+#include <QtCore/QMetaType>
+#include <QtCore/QString>
+
+class BonjourRecord
+{
+public:
+    BonjourRecord() {}
+    BonjourRecord(const QString &name, const QString &regType, const QString &domain)
+        : serviceName(name), registeredType(regType), replyDomain(domain)
+    {}
+    BonjourRecord(const char *name, const char *regType, const char *domain)
+    {
+        serviceName = QString::fromUtf8(name);
+        registeredType = QString::fromUtf8(regType);
+        replyDomain = QString::fromUtf8(domain);
+    }
+    QString serviceName;
+    QString registeredType;
+    QString replyDomain;
+    bool operator==(const BonjourRecord &other) const {
+        return serviceName == other.serviceName
+               && registeredType == other.registeredType
+               && replyDomain == other.replyDomain;
+    }
+};
+
+Q_DECLARE_METATYPE(BonjourRecord)
+
+#endif // BONJOURRECORD_H

include/bonjour/bonjourserviceregister.h

@@ -0,0 +1,66 @@
+/*
+Copyright (c) 2007, Trenton Schulz
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice,
+    this list of conditions and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ 3. The name of the author may not be used to endorse or promote products
+    derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef BONJOURSERVICEREGISTER_H
+#define BONJOURSERVICEREGISTER_H
+
+#include <QtCore/QObject>
+
+#include "bonjourrecord.h"
+class QSocketNotifier;
+
+#include <dns_sd.h>
+
+class BonjourServiceRegister : public QObject
+{
+    Q_OBJECT
+public:
+    BonjourServiceRegister(QObject *parent = 0);
+    ~BonjourServiceRegister();
+
+    void registerService(const BonjourRecord &record, quint16 servicePort);
+    inline BonjourRecord registeredRecord() const {return finalRecord; }
+
+signals:
+    void error(DNSServiceErrorType error);
+    void serviceRegistered(const BonjourRecord &record);
+
+private slots:
+    void bonjourSocketReadyRead();
+
+private:
+    static void DNSSD_API bonjourRegisterService(DNSServiceRef sdRef, DNSServiceFlags,
+                                       DNSServiceErrorType errorCode, const char *name,
+                                       const char *regtype, const char *domain,
+                                       void *context);
+    DNSServiceRef dnssref;
+    QSocketNotifier *bonjourSocket;
+    BonjourRecord finalRecord;
+};
+
+#endif // BONJOURSERVICEREGISTER_H