MSNP16 code

[Jorge Villaseñor]

The MSNP16 code is functional and I think it's ready to be widely
tested. To this end I have closed the ticket #8247.

If you find any issue in MSNP16 it's better to open a new ticket so we
can track the issue down and fix it.

I do want to ask for some comments on my plan about this code.

* Merge the new SLP code from the SoC to this branch, and test both
changes at the same time
* Test and merge msnp16 branch to im.pidgin.pidgin and after that,
test and merge the new SLP code (which is based on the msnp16 branch).


-- 
Masca