Use a gdbus-codegen-ed GDBusInterfaceSkeleton and GApplication

... instead of manually acquiring the bus, registering objects on it,
dealing with the details of handling methods and parameters,
unwrapping parameters from GVariant, dealing with timeouts, etc..

https://bugzilla.gnome.org/show_bug.cgi?id=731976
Remove unused MINER_OBJECT_PATH

https://bugzilla.gnome.org/show_bug.cgi?id=731976
src: Pass the content type to RefreshDB

Add an array of strings as argument to RefreshDB to denote the type of
content we are interested in indexing.

https://bugzilla.gnome.org/show_bug.cgi?id=728878
Prepare 3.13.3