Message -> Item and Category -> Question Type

Added network_provider column to ItemTable, and ensure it's not displayed in the table widget. Also ensure the widget doesn't display the 'select_item' column, previously named 'delete'.

Ensure we use the right taxonomy for the question category. The taxonomy in use is still hard-coded, as that is something we will look at later - this commit was only intended to restore functionality to the existing level.

Re-introduce the per-row drop down to update each record's category as well as the mirrored buttons at the bottom of the page. This means that we have a single form that can either do a batch update, or an update of values set per row. The different action is determined by the submit button that was used - which is always named 'action'. Because we have a mirrored select drop down for the batch action, we need to know which one to take into account - so the value of the submit button indiciates which one was clicked, of the form <action>-<placement> (eg. save-top) and the name of mirrored inputs indidicate where they are located, of the form <name>-<placement> (eg. batchaction-bottom). The ViewItems class has a static method to find the active placement and rename the parameters accordingly. Some of the old code was re-introduced, though some of it was refactored (eg. what used to be get_categories, to fetch each row's selected category, has been moved to ItemTable to parallel get_selected, and is now named get_row_select_value (it's a more generic version, looking at the future when we'll update the region with the same mechanism.)

Rename select_action to select_item which makes more sense. Rename the checkbox itself select_item_id to allow other types of selectes in the future. Move the code to determing selected items into ItemTable since this is where the form is generated, and we know how it was build.

Refactor the 'select all checkboxes' javascript into a separate file so it can be used on other tables easily. Add a test for the select all checkboxes javascript. Remove the label from the 'delete' column (which is now a 'select all' column as we may have other actions) and move it to the first column as per balsamic mockups.

Use accessor to fetch out the name of the first term
(assuming there will be at most one)

And the get_category function isn't needed any more
because its the shrot name that gets compared in the template
to decide which is selected.

Categories on the view/edit screen no longer have hard coded values
but instead read the available terms from the database