Added sqlite capability.  

To summarize:
* SQLite uses ? as the param style, which we need to use when dynamically building our values list for our insert statement.   This caused me to make changes to events.py and stats.py, more extensively to the latter.
* After testing the changes due to the previous bullet, I went back and tested for postgresql.  It became necessary to insert conditionals if sqlite was being used.  To facilitate this, I created a global _config variable and checked the database type when the necessary.
* Added sh_toi column to gamelogs_skaters table for the postgres schema script..
* Removed the 'nhl' schema and made other noted changes to the lookup sql scripts.

Tested all changes with postgres 9.1.11 and sqlite 3.7.15.2 on Ubuntu 13.04.