[keycloak-dev] Added server version to cached resource urls

[Stian Thorgersen]

Every time we release a new version we get a lot of people having problems with the admin console. Usually these are due to the browser caches old Angular templates.

I've made a change to themes so instead of a resource being loaded from:

  /auth/theme/<type>/<theme name>/<resource>

It's now retrieved from:

  /auth/resources/<server version>/<type>/<theme name>/<resource>

Also, I've changed index.html for the admin console to index.ftl so that I could add the resource path (including server version, admin theme name, etc.).