Remove old authentication tests.
Create new SecurityExceptions, store roles in User object.
Add access to type-level annotations to RPC CallContext.
Fix client-side interceptors (need to write a few more tests).

Also removed CodeDecoration for @Require* annotations (needs to be
redesigned).
Add/fix javadocs in errai-security.
Add 'logout' handling to LoginInterceptor.
Fix default error handling of client-side rpc when error occurs in interceptor.
Use uncaught exception handlers for client-side redirection when security errors occur.
Remove error handler from hello RPC in security demo (to allow login redirection).
Reload page after login if no previous page found in cookie.
Factor out unneccessary ClientSecurityInterceptor class from errai-security. Use cookies when navigating from security exceptions.