Travis-CI: IRC channel moved to freenode
Build: removed duplicate StarkSoftProxy project reference
Revert "Build: removed duplicate StarkSoftProxy project reference"

This reverts commit aa17201dca0b513ccb7c91d7d325ba5aca898c3b.

This duplicate reference is needed to allow building agsxmpp.sln with xbuild
like Travis CI does.
casting a null Jid to string caused NRE, casting null string to Jid returned a valid Jid object