Updated schema, collapsed Batter and Pitcher into Player, and Player can have both BatterProjections and PitcherProjections
Chadwick register step uses separate function from read_projection_csv
Index on ID fields
Fix up Chadwick header rows (at least w/r/t the 4 Mar file), and add_or_update_player only checks on mlb_id and fg_id, for speed purposes
Proper handling of unique ids
Starting to restore/write actuals data stuff
Fangraphs actual data batter load works
Pitcher actuals now work, temporarily commented out other projection loads; also added get_projection method on player
Fixed a few bugs, now PECOTA all works, Steamer works 2011-2013 after a few manual data fixups
All works but PFM