export source now detects the prefix rather than assigning it based on filename. fixed up some comments to match our coding standard. added ability to set default license on export which will be useful for the next source drop. SL-56607

svn merge --ignore-ancestry svn+ssh://svn/svn/linden/release@65088 svn+ssh://svn/svn/linden/branches/release-candidate@65078 -> release Paired by Tess and rdw.

SL-38184 Make python scripts in linden/scripts run in place without PYTHONPATH or symlinks.  Reviewed with Donovan.