Add MapMarker and MapBubble classes

These are base classes intended to create markers associated with
content rich popovers.

https://bugzilla.gnome.org/show_bug.cgi?id=722871
Refactor user location marker to support bubble

https://bugzilla.gnome.org/show_bug.cgi?id=722871
Replace MapLocation with SearchResultMarker,Bubble

https://bugzilla.gnome.org/show_bug.cgi?id=722871
Fix wrong margin in RTL in the sidebar

https://bugzilla.gnome.org/show_bug.cgi?id=732194
mapView: Guard against geoclue not present
Release 3.13.4
Popovers test
Merge branch 'master' of git://git.gnome.org/gnome-maps
update marker selected method