getter of overridden/original package name

git-svn-id: http://protostuff.googlecode.com/svn/trunk@1623 3b38d51a-9144-11de-8ad7-8b2c2f1e2016
cache sourcePath

git-svn-id: http://protostuff.googlecode.com/svn/trunk@1624 3b38d51a-9144-11de-8ad7-8b2c2f1e2016