core: Set G_MESSAGES_DEBUG when parsing debug domains
core: Set G_MESSAGES_DEBUG when parsing debug domains

This stops GLib from dropping all our debug output (unless the user has
remembered to set G_MESSAGES_DEBUG manually in addition to FOLKS_DEBUG).

GNOME/folks,renatofilho/folks2,pwithnall/folks,pwithnall/folks,renatofilho/folks,renatofilho/folks,GNOME/folks,renatofilho/folks2,pwithnall/folks,renatofilho/folks,renatofilho/folks,GNOME/folks,renatofilho/folks2,renatofilho/folks2