Release notes for 0.5.10.1

Tickets fixed on this release:

#113
    INVITE transaction is not destroyed immediately when ACK has the same branch as the INVITE
#115
    Release 0.5.10 does not have the correct PJ_VERSION string!

For the main features released on 0.5.10, please see http://www.pjsip.org/trac/milestone/release-0.5.10.