[Telepathy] TelepathyQt in GSoC 2016, ABI issues

[Daniel Pocock]

There are several TelepathyQt-related projects in GSoC under Debian this
year:

https://summerofcode.withgoogle.com/organizations/5023548368224256/?sp-page_size=48

To make things easier for students (and the wider pool of mentors who
may be testing their work) it will be helpful to address some ABI issues
and shared library packaging:

- if the ABI is changing on each release, should TelepathyQt libs use an
SONAME such as libtelepathy-qt4-0.9.6.so.0 ?  Currently it is
libtelepathy-qt4.so.2 - that was used for both 0.9.4 and 0.9.6 but I'm
not sure if they are ABI compatible?

The reSIProcate project uses the version-in-SONAME convention, e.g. when
you build the 1.10.1 or 1.10.2 release, you have the SONAME
libresip-1.10.so and all releases in the 1.10.x series are guaranteed to
be ABI compatible.

- the libtelepathy-qt?-service.so needs to be in the packages as a
shared object.  The concerns about the stability of this API/ABI can
probably be addressed by the SONAME proposal above.