Initial commit with lots of stuff

- Reorganized project structure so each sport has its own directory.
- Created baseball-reference scraper that currently goes through each
list of players (A-Z) and visits each player’s season stats page.
Added a constants class
Scraper now sleeps 5-10s after parsing player names from list.
Added parsing of the pitcher Standard Pitching table for season stats.
Added constants for "Player Value--Pitching" table
Added parsing of "Player Value--Pitchers" table.
Merge branch '20140328_add_baseball'