Merge patch from Giulio Paci that uses libhidapi if libhidapi-libusb does not exist. Fixes compilation on FreeBSD.

main.cpp

@@ -203,10 +203,5 @@ Example:
 
   }
 
-  /*k.setMode(MODE_NORMAL);
-  k.setColor(REGION_LEFT, COLOR_RED, INTENSITY_HIGH);
-  k.setColor(REGION_MIDDLE, COLOR_PURPLE, INTENSITY_HIGH);
-  k.setColor(REGION_RIGHT, COLOR_SKY, INTENSITY_HIGH);*/
-
   return 0;
 }

msi-keyboard.pro

@@ -10,5 +10,14 @@ SOURCES += main.cpp keyboard.cpp
 HEADERS += keyboard.h
 
 QMAKE_CXXFLAGS += -std=c++11
+QMAKE_LFLAGS   += -Wl,--no-undefined
 
-unix:LIBS += -lhidapi-libusb
+packagesExist(hidapi-libusb) {
+  unix:LIBS += -lhidapi-libusb
+} else {
+  packagesExist(hidapi) {
+    unix:LIBS += -lhidapi
+  } else {
+    unix:LIBS += -lhidapi-libusb
+  }
+}