Stop relying on lunaservice.h to include glib.h

In order to use the luna-service2 routines that require GLib, <glib.h>
must be included before lunaservice.h .

[OWEBOS-3048] Remove #include <glib.h> from lunaservice.h

Open-webOS-DCO-1.0-Signed-off-by: Herb Kuta <herb.kuta@palm.com>
Merge pull request #20 from kuta42/include-glib.h-before-lunaservice.h

Stop relying on lunaservice.h to include glib.h