Putting migratedb in group_vars/all overrides any vars
in playbook files and so migrations never get run.

* should be *_debian_pkgs instead of *_debian_packages
* removed duplicate task

specific

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.

* Creates global variable $platform_code_dir to store
  /opt/wwc/edx-platform, to replace the semihardcoded /opt/wwc/mitx that
  we had before.
* Plugs $platform_code_dir in a lot of different places
* Templatize sef's update script hack

* Touches directories and files into existence expected during setup for
  LMS and CMS
* Configures rsyslog to catch local0 and local1 from edx, and route into
  the appropriately named files in the appropriately named
  subdirectories
* Permissions updates to ensure rsyslog can write everywhere it's
  supposed to
* Restarts rsyslog after reconfiguration is complete

* I've moved the example secure directory to playbooks/secure_example,
  the directory structure in your secure repo should mirror that in
  secure_example/
* If you run the lms role without a valid git-identity file it will
  fail, there is an empty file checked into the secure_example dir
* Using GIT_SSH env for git checkout, we will also need to use that
  for pip installs that use git if there are private repos in
  requirements.

* Move debian package list to roles/lms/vars/main.yml
* Move lms_git_repo to roles/lms/vars/main.yml

* Create a global variable lms_source_repo to make it easy to update
  where to pull mitx from when mitx moves
* Create global variable venv_base to store location of edx virtual
  environment, defaults to /opt/edx
* Create edx virtual environment to store python modules
* Add tags to LMS and CMS tasks to make selective running and testing
  easier
* Install a long, static list of debian packages, which has been
  manually curated from other edx configurations; this probably needs
  more attention and in the future should probably be divided better
  among various roles.
* Install the list of python packages distributed with the mitx
  repository
* Install some really useful software, namely mosh and tmux

By default it installs 1.9.3-p374 in /opt/www/.rbenv and gems go
in /opt/www/.gem, which replicates the vagrant box

Also changed top level playbook ymlv var search to follow a path, first
over {{ secure_file_dir }} set in group_vars/all then at
vars/secure_default

* Replace hardcoded instances of /opt/wwc with $app_base_dir, which
  defaults to /opt/wwc.
* Add tags to nginx tasks so they can be selected independently.

This keeps vars that are specific to roles with the role, not
very well documented except in the playbook example here:
https://github.com/ansible/ansible/blob/devel/examples/playbooks/roletest.yml

This makes playbooks more concise since you do not have to explicitely
include vars for each roles, var_files will still override any of the
default values in <role>/vars/main.yml

* New role for nginx, main.yml will install the nginx package
* By default create the basic version nginx config
* Add variables for nginx package version and template in group_vars/all
* Refresh apt-cache in common role

* Created new directory structure outlined in the README
* Created the LMS role which for now just creates teh application config
files
* Created the common role
* Updated the cf playbook to accept arguments