Remove unused controllers and views

* Delete the following:

  SFDC_users_controller
  test_forces_controller
  sfdc_users/index.html.erb
  test_forces/index.html.erb
  users/_signin.html.erb
  users/_signup.html.erb
  users/welcome.html.erb
Load clients map on index page of session controller
Combine old sfdc_users and users controllers

* Move sfdc_users controller actions to user controller
* Rename controller actions to be more RESTful
Clean up routes

* Use RESTful routes
Add controller for login/signup page
Add/move views

* Create index views for sessions, users, and welcome
* Move signup and signin views from users to welcome directory
Merge branch 'master' into md-wo-cleanup-routes-ctrls
Merge pull request #25 from wh1tney/md-wo-cleanup-routes-ctrls

Huge refactor of routes, views, and controllers