Clean-up ProjectConfig to use common interface for persisting all
configuration types.
Removed unnused API: InjectPanel and CreatePanel
Implemented ERRAI-723: Add gatekeeper-like functionality to IOC
Reverted changes in jax-rs demo that I committed by mistake
Apply style with @RestrictedAccess stylebinding instead of setting
"display: none".
Add RestrictedAccess CSS class name to docs.
Support multiple style binding annotations on a data field
Removed @Alternative configuration for AuthenticationService tests
Support for overriding template styles using style bindings
Style binding optimization (bean creation no longer causes all active beans to update)
Removed debugging statement
Created annotation processors that verify correct usage of the ErraiUI annotations. Disabled by default.
Merge parts of Uberfire Security into Errai. Details below.

* Imported UberFire's Role and Subject (now User) types; standardized Errai security on these

* Centralized the role membership checking logic onto User; added unit tests for it

* Refactor ActiveUserCache into SPI.

* Create ANONYMOUS user constant to use instead of null when no user logged in.

* Switch to cookie storage of user info so that we can unify with UberFire's form based login

* Use cookies instead of local storage; add CookieEncoder class into shared package.

* Make todolist demo user an errai security User.

* Delete Identity class (it's redundant; Caller<AuthenticationService> can be used).
Update security documentation to reflect uberfire-merge changes.
Don't pass in null Throwable to SimpleFormatter in client-side logging (to avoid printing 'null' when no exception)
Avoid unnecessary calls to updateStyles after bean destruction
Fixes and minor improvements to security docs
Removed aerogear wrappers
Fixed ValidationRulesTest
Removed app engine dependency