Update to Qt 5.12.0.

Project files with MacOS clang RPATH to use proper paths for shared objects.
Minor path updates in favor of loading plugin libs.
Deployment script packaging using Qt way(macdeployqt).

plugins/samplesource/hackrfinput/hackrfinput.pro

@@ -54,4 +54,8 @@ LIBS += -L../../../swagger/$${build_subdir} -lswagger
 macx:LIBS += -L/opt/local/lib -lhackrf
 LIBS += -L../../../devices/$${build_subdir} -ldevices
 
+macx {
+    QMAKE_LFLAGS_SONAME = -Wl,-install_name,@rpath/
+}
+
 RESOURCES = ../../../sdrgui/resources/res.qrc