Fix bug: grab image negative quality isn't 100.

ChangeLog

@@ -1,6 +1,7 @@
 User johns
 Date:
 
+    Fix bug: grab image negative quality isn't the default 100.
     Support AMD VDPAU with surface size != requested size.
     Add cache for auto-crop buffer.
     Fix opengl and opengl threads bugs.

softhddevice.cpp

@@ -2512,6 +2512,9 @@ uchar *cSoftHdDevice::GrabImage(int &size, bool jpeg, int quality, int width,
     if (SuspendMode != NOT_SUSPENDED) {
 	return NULL;
     }
+    if (quality < 0) {			// caller should care, but fix it
+	quality = 95;
+    }
 
     return::GrabImage(&size, jpeg, quality, width, height);
 }