fixed bug backing up a shared XML backend project

Change-Id: Iaf9d78458472676574d9798bed34147a8518b9bd
clean up project restore in Paratext lexicon plugin

Change-Id: Ifaaa5034d8dcb5cf56b0c14b30dac8b9623e15f2
get code dir in PT lexicon plugin from current plugin location

Change-Id: Ibea465e614e05387d02d387c9ae8f7e96c15e6d7