Create UserActions mdoel to track user actions

Create a UserActions model, which belongs to User and has an associated record + action.

Also create an AuditWrapper, which makes it easy to add an audit event to a model
remove AppOauthScope model
updated header to only show not me on auth page
using rails helper instead of string
Merge remote-tracking branch 'origin/devel' into feature/user_audit

Conflicts:
	config/initializers/doorkeeper.rb
	db/schema.rb
Refactor Audit class/modules

Extend UserEvent audit methods in ActiveRecord::Base so that any model can call audit_on with minimal boilerplate.
Increase limit of authentication_tokens#return_to to 2000
Merge pull request #239 from 18F/hotfix/increase_limit_for_authentication_tokens_return_to

Increase limit of authentication_tokens#return_to to 2000
resolving dependency on request object
Partner App Logout

Supports a redirect after logout.  By passing "continue=<url>" as a logout
parameter, an app can redirect the user back to any sub-url of their site.  In
order to be allowed, the redirect URL must be a hostname that ends with the
same string as an application's URL, for an application approved by the user.
Merge branch 'devel' into feature/api-logout

Conflicts:
	app/controllers/application_controller.rb
Don't show scope groups for groups not requested

If the filtered scopes (requested scopes) for a particular
scope group is empty, don't show the scope group <li>
and <h2> tags (don't show the group at all, really).
Implement requested changes from #191

Account --> Your Profile
This is not me --> functional sign out link

There's an issue where "This is not me" should allow switching
of accounts.  Will file an issue for that.
Merge pull request #233 from 18F/feature/not-me

Only show This is Not me on the oauth authorize page
Merge pull request #242 from 18F/hotfix/limit-scope-groups-ui

Don't show scope groups for groups not requested
Merge branch 'devel' into feature/api-logout
Update Aglio Docs
Merge pull request #241 from 18F/feature/api-logout

Partner App Logout
Add remote_ip and created_at to UserAction model

Add remote_ip and created_at to UserAction model. Also add a 'Sweeper' to the
audit classes so that we can intercept a UserAction.create and add remote_ip
(and current_user) to the record. Also add Warden hooks for after_set_user and
before_logout so that we can audit sign_in and sign_out events.
Merge remote-tracking branch 'origin/devel' into feature/user_audit

Conflicts:
	db/schema.rb