WUI: Updated resource loading

- In order to load all resources also for devMode, loading
  of CSS and images was changed.

  They are now part of ClientBundle and must me injected to
  page when module requires it (CSS, images).

  FavIcons are base64 encoded in HTML page for local loading.

- Allow to build production profile from parent pom.xml
  using "-Dproduction" parameter.

- Fixed language recognition if browser returns stuff like cs-cz.
WUI: Bumped to GWT version 2.7.0

- Fixed loading logo in wui-admin.
- Removed unused dependency from pom.xml
- Removed Opera permutation since it's not supported by
  GWT 2.7.0

- Thanks to new version of GWT we can now run superDevMode
  from command line like: "mvn gwt:run". It will start both
  servers and new mode again recompiles on browser refresh.
WUI: removed unused property from pom.xml
Merge upstream/master

Conflicts:
	perun-wui-admin/src/main/java/cz/metacentrum/perun/wui/admin/client/TopMenu.java
	perun-wui-core/src/main/resources/common/cz/metacentrum/perun/wui/resources/css/PerunWui.css