refactored Where_pre subroutine for readabillity
new subroutine: get_single_value_from_db()
added pod Doc and relocated subroutine into correct package
further progress in implementing feature
added error handling and logs to 2 new functions
nicer log output with hints, completed the 2 subroutines
completed POD documentation of new subroutines.
Added wherePre support to new functions
Added inline Doc for Where_Pre
modified get_single_value_from_db to use $options dictionary
Merge pull request #42 from pRiVi/comfortable_get_data_set

Added pod Doc + 2 new subroutines for more comfortable get data set (wrappers)