Added congregation.py to handle congregation related functions
Added new dialog to enter and edit congregations.
Switched out QTableWidget for QListWidget
Replaced get_item() with return_pass_sql. The later of the two takes a SQL code and passes it to SQLite
Modified the get_list method to be simpler.

Got rid of the un-needed list variable. It served to purpose.
Few changes while implementing pop_table method for the CongregationWindow

Renamed pop_table() with populate_table(). Aslo removed the debugging code and added code that populates a list of congregation from the database into the list_congregation list.