Added requirements.txt

This allows you to:
  pip install -r requirements.txt
Removed SES dependency for development. Fixed bug where DEVELOPMENT was used before being overridden by local_settings.py.
Fixed doc. We do require a non-fake migrate as well.
Expanded requirements
Documented additional hack to get into the system without Stripe installed
Merge pull request #221 from pmitros/master

Slightly simplified development install