[keycloak-dev] Theme support for admin console

I'm working on adding theme support to the admin console, and the plan was to use the what we have for login and account forms. To get this to work I can either use a Servlet or a JAX-RS endpoint to deliver resources. My preference is to use JAX-RS and have everything done through RestEasy, effectively dropping Servlets (and web fragments). This would also let us drop '/rest' from the other endpoints (so it would be '/realms/keycloak-admin/tokens/login' instead of '/rest/realms/keycloak-admin/tokens/login').