Add-ons: SamePlace and xmpp4moz

[Sam Geeraerts]

The following extensions are free software:

Name: SamePlace
Website: http://www.sameplace.cc/
Description: Instant messaging client
License: GPLv3 (LICENSE file and practically every source code file has 
a license notice)

Name: xmpp4moz
Website: http://www.sameplace.cc/ (included in SamePlace suite extension)
Description: XMPP library
License: GPLv3 (No license file, but project license stated on the 
website and practically every source code file has a license notice. 
There's a small issue with xpt binaries that come from a third party [1].)

[1] https://answers.launchpad.net/sameplace/+question/86666