support registration and login via apache + mod_wsgi + mod_shib

Note that we now thing that gunicorn and mod_wsgi should not live
on the same machine if they are running the exact same codebase
with the exact same edx logging directories.  This seems to
cause deadlock at random times

Feanil/edxapp gunicorn

Jarv/edx sandbox

also adding comments

Configured to use localhost for mongo, mysql, memcache

Run only when migrate_db is set which will be the case
for bringing up new instances

This allows you to access services without setting
up subdomains

edx_sandbox for edx-east and an edx_sandbox reference
new launch_instance role for bringing instances up using the ec2 module
new edxlocal role for installing local dependencies

These handlers aren't being used by anyone and have been superceded by
the handler that starts and stops all edxapp components.

Allow the bastion box to reach all IPs on the 10.0.x.x subnet.

Jbau/new edx theme

This commit basically does 3 things:
* Creates symlinks within the playbooks/edx-west directory
  to allow ansible-playbook to be run in that directory
* Adds support for creating theming directory and checking out
  themed git repo into that directory at deploy time.
* Moves around some of the edxapp deploy handlers.
  Also tags them all with - deploy, so that running
  ansible-playbook with --tags=deploy basically just deploys.
  Also splits restart edxapp into stop and start edxapp b/c
  restart wasn't working on Stanford servers.  Could debug
  this later, probably best by looking at the edxapp upstart script.

allow ini file setting via environment variable

Extend ec2.py to accept an ini file

* End the constant reversion of ec2.ini preferences by allowing ec2.py
  to accept an ini file on the command line, and checking in an ini for
  edx-west that suits their needs.

Feanil/documentation

Feanil/ansible deploy

Tasks that should be re-run when a new version of the code
is installed are now handlers that are notified once the code has
been checked out and the directory is ready(ownership change).