Removes non-useful options in EOS page tree menu

= Options after clean up.
== Slot menu
 * Add component
 * Access rights

== Component menu
 * Delete component
 * Change component
 * Create page part template
 * Component properties

All remaining options can be disabled through IPs.
The menus can now be empty with certain configurations. Therefore a
concept for handling this has been added. Now a "no action" menu option is
displayed if no real menu options are available to the user.

Also adds IP for disabling the component properties menu options. This IP
can be applied on a slot by slot basis.
Merge pull request #81 from stenbacka/eos-tree-menu-cleanup

Removes non-useful options in EOS page tree menu