create more tests

[splitbrain]

A few things currently seem to work fine but are not covered by tests:

• revert action
• page deletion
• enable/disabling of fields (check in search, entry, table)
• config clearing in Types
• AbstractBaseType functionality
• diff showing
• access level checking in search
• assignment/deassignment in Handle Assignment/Deassignment as discussed in #28 #33
• the functions in Value
• User Type WIP: Implement Type User #41
• skipempty in SchemaData::getData*
• SchemaData::clearData()
• field sorting
• search distinct
• config parser
• visibility handling
• bureaucracy support

Pull Requests welcome!

[micgro42]

Isn't the test for page deletion already done in action_plugin_struct_entry::test_delete_page?

[splitbrain]

confirmed, page deletion is tested already.