Apa102 fix if the led strip has more physical LEDs than you want to configure with hyperion (#626)

* 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

* started bug fixes for APA strips with more physical leds than configured

* 1st cut of changes to APA102.

now looks at config for "leds" which is the # of hardware leds in the strip.
This enables us to write the correct trailer length in the packet.

Also fixed a bug where switchoff was writing the wrong # of leds

* removed commented out old code

removed debug printf

* included prebuild test binary for Pi2

* Second attempt at the fix.
BEFORE:
If you have more physcial LEDs than defined in the "leds" "index" section of the config there is random junk added to the end of the strip.

WITH THIS FIX:
In the "device" section specify the number of physical leds with:
 "leds" : 212,
If this is greater than the number of led indexes, additional LEDs are set to black
If this is smaller than the number of led indexes, it is ignored

* included test binary

* Clean exit if the device config is missing or a non-supported device type is specified

Former-commit-id: 8ae96188fa74d91b13a921e7d5faf6d6ac1c42ee

libsrc/leddevice/LedDeviceFactory.cpp

@@ -124,8 +124,9 @@ LedDevice * LedDeviceFactory::construct(const Json::Value & deviceConfig)
 	{
 		const std::string output = deviceConfig["output"].asString();
 		const unsigned rate      = deviceConfig["rate"].asInt();
+		const unsigned ledcount  = deviceConfig.get("leds",0).asInt();
 
-		LedDeviceAPA102* deviceAPA102 = new LedDeviceAPA102(output, rate);
+		LedDeviceAPA102* deviceAPA102 = new LedDeviceAPA102(output, rate, ledcount);
 		deviceAPA102->open();
 
 		device = deviceAPA102;
@@ -349,6 +350,7 @@ LedDevice * LedDeviceFactory::construct(const Json::Value & deviceConfig)
 	{
 		std::cout << "LEDDEVICE ERROR: Unknown/Unimplemented device " << type << std::endl;
 		// Unknown / Unimplemented device
+		exit(1);
 	}
 	return device;
 }