json-glib as an external dependency for 2.31/3.0

[Emmanuele Bassi <ebassi gmail com>]

hi all;

Clutter has been using an internal copy of JSON-GLib for a while, but
the plan with 1.x was to switch to the system copy and use the internal
copy as a fall back meant for quick portability and testing on new
platforms. the internal copy is synchronized usually before new release
cycles, but it's not a strictly compliant JSON parser (it does not parse
escaped UTF-8 sequences '\uXXXX').

I'm thus proposing to add JSON-GLib to the external dependencies for
2.31/3.0. json-glib LGPLv2.1+; it is hosted on gnome.org for Git and
Bugzilla; and it is already shipped on most distributions.

ciao,
 Emmanuele.

-- 
W: http://www.emmanuelebassi.name
B: http://blogs.gnome.org/ebassi