core: Listen on primary-store settings changes

https://bugzilla.gnome.org/show_bug.cgi?id=731470
tests: Add test for primary-store setting changes

https://bugzilla.gnome.org/show_bug.cgi?id=731470
build: Allow building with Tracker 0.16, 0.18 and 1.0

Allow configuring against one of several versions of Tracker. This uses
the chained PKG_CHECK_MODULES technique from
https://www.flameeyes.eu/autotools-mythbuster/pkgconfig/pkg_check_modules.html#idm103041829189696

Based on a patch by Maciej Piechotka <uzytkownik2@gmail.com>.

https://bugzilla.gnome.org/show_bug.cgi?id=728520
Release version 0.10.0
Post-release version bump
Updated Marathi Translations