telepathy: Remove unused variables

Fallout from bf26d062f46a27086440f61e67884de6b8be07b7

Fixes: https://bugzilla.gnome.org/728787
Prepare 3.13.1
build: Remove deprecated call to GNOME_COMMON_INIT

It just sets ACLOCAL_AMFLAGS, which is already correctly set in
Makefile.am.

Also remove a duplicate AC_CONFIG_MACRO_DIR call.

https://bugzilla.gnome.org/show_bug.cgi?id=729389
Add Check-In feature and use it in Facebook provider

Also, clear the code of build_object method.