[External Deps] Issue in libtelepahy deps

[Luca Ferretti <elle uca libero it>]

Building meta-gnome-proposed in jhbuild, I found a "hole" in external
deps. 

Currently empathy is proposed for 2.22, suggesting[1] libtelepaty and
libmissioncontrol as external deps[2].

But in order to build libtelepathy you need "telepathy-glib" too; this
module isn't prosed for inclusion as ext dep for 2.22.

Question A: should we consider telepathy-glib a proposed dep?
Question B: if the answer to previous question is yes, OK to update wiki
pages and jhbuild modulesets?
Question C: shouldn't we use released packages for external deps
(currently all *telepathy* packages are grabbed from version control)?

[1] http://live.gnome.org/TwoPointTwentyone/Desktop
[2] while both not listed as suggested in    
    http://live.gnome.org/TwoPointTwentyone/ExternalDependencies