fix bug on DBUS

sorry for 45d6dbddaa114d5d054836f6829241481ead2442
Normally, the HAVE_XXX is defined to 0 or 1.
I commit it without build. However, I build and find, and figure it.
fix dbus build on MAC OS X
fix configure message for GTK3
fix configure message for duplicate GSTREAMER
Merge pull request #37 from liudongmiao/master

fix bug on DBUS