Webclient: rename 2 view config settings (#208).

BREAKING CHANGES

2 view configuration settings are renamed:
    "Add To Create Menu" -> "Show in Create Menu"
    "Is Searchable Unit" -> "Searchable as Unit"

The corresponding URIs are changed accordingly:
    "dm4.webclient.add_to_create_menu" -> "dm4.webclient.show_in_create_menu"
    "dm4.webclient.is_searchable_unit" -> "dm4.webclient.searchable_as_unit"

In your plugins you must perform an URI search/replace, particularily in the JSON files.
You must reset the DB.

See ticket 208.