Convert to south and add session_key

updated .gitignore
Fix errors with django 1.4 timezone support

**Removed compatibility with django1.3**

Simplify get first and last day of the month
Fix error - check if session available on request object
Memory bulk_create for requests

Added a settings var to store an array of requests. By default, 0.
Added classmethod for from_http_request
Implement custom time auto_now
Refactor from_http_request and added get_open_sessions_from_users

Split from_http_request, removing the save object and moving it to a @classmethod
Create a new function that list for a list of users the last requests
Merge branch 'master' of https://github.com/kylef/django-request into update1.5

Conflicts:
	request/models.py
Render exceptions on init and try on bulk_create
Cache requests optionally
Refactored Request class methods to the class manager
Added function Request manager to persist cached requests
Changed Request manager function from get_open_sessions_from_users to get_open_session_keys_from_users
Merge pull request #1 from marccerrato/persistence-optimization

Requests persistence optimization by using cache (optional)
update django 1.6
Merge pull request #1 from jasuca/master

Updating Repo for Django 1.6 Support