* Added log4net dependency to physxplugin in prebuild.xml.
* Added missing m_log fields to classes.
* Replaced Console.WriteLine with appropriate m_log.Xxxx
* Tested that nant test target runs succesfully.
* Tested that local opensim sandbox starts up without errors.
Many issues with handling connections in MSSQL, have rearchitected to
ensure that connections are always opened and closed in a timely fashion
& disposed of cleanly, and removed unnecessary lock statements. SQL
Server performance seems to have improved considerably as a result,
and various timeout errors seem to have been fixed.