* 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.
DNE and move all of DNE into the DotNetEngine directory. Remove references
that would cause the script runtime to load the entire engine + scene into
each script appdomain. This might help DNE memory consumption.