[sr-dev] porting opensips rls fixes to sr

[Juha Heinanen]

i have been so far using opensips for presence, but now due to OMA/RCS
enhancement by peter, i'll give sr presence a try. there has been
several bug fixes and enhancement to opensips presence after the split
that have not been included in sr.

i'll to port some of them to sr during the following days.  please
comment, if you see problems with any of them.

-- juha