Added init_db to remove "AttributeError: 'MSSQLConnector' object has no attribute 'init_db'"
Solving "AttributeError: 'MSSQLConnector' object has no attribute 'get_connection'"
Solving "NameError: global name 'MSSQLConnection' is not defined".
Solved "TypeError: Can't instantiate abstract class MSSQLConnection with abstract methods cast, concat, drop_table, get_column_names, get_last_id, get_table_names, like, like_escape, prefix_match, prefix_match_value, quote, update_sequence".

Also removed ODBConnection class.