notify: delete stragne asserts
notify: change actoin ids to well known
lastfm: make callbacks static
lastfm: avoid touching current mobj from non-main thread
get rid of curr_mobj_mutex

Now the current mobj get accessed from main thread only
playback: fix mem leak
dbus: fix crash on get current state
Merge branch 'master' into GobjectTagsDialog

Conflicts:
	src/pragha-lastfm.c
	src/pragha-menubar.c
	src/pragha-tags-mgmt.c