Suppress Cache Actions for Users

The three actions to refresh the current page, the current page tree, and the doctype cache should not clutter the UI. These actions are (hopefully) only relevant for projectdoc developers.

Therefore add a condition such that these actions are only displayed if (all must match):

• the current page is labelled with "projectdoc" (this will remove those actions for all other pages)
• the user has edit permissions on the current page (this will remove this from all readers)
• the user is in group "projectdoc-developers" (this will remove this from all authors)

In case there are users that will benefit from these actions, they may be added to the "projectdoc-developers" group. This may be helpful in cases where there are problems with imports (or bugs in the plugin) that prevents the pages from being stored to the database and added to the Lucene index.