[Android] Issues #424, #411, #409 Fixed 

#424 - [Android] Sqlite insert performance on pull can be significantly improved
#411 - Throwing a conflict exception for facilitating duplicate handling
#409 - Purge should throw instead of doing a push
The transformation is taking place on the "executeTableOperation" method that is called from the "update" and "delete" methods. 
In the case of an exception the "executeTableOperation" method put the transformed exception into the future exception result, so there is no need to translate it again.