Merge branch 'view_and_edit_technical_debt' of git.aptivate.org:internewshid into view_and_edit_technical_debt

-- view-edit screen has no padding around table
-- developed by aptivate - disappears on smaller screens
-- view-edit screen has no padding around table

-- page-title disappears under header on tablet width
-- page-title has no padding/margin on left side on smaller screen

Refactor add_items_categories and add_categories into a single call, and make the taxonomy slug configurable at that level (it's now hard-coded in process_items). Update tests to match the change and ensure we can update multiple items at the same time.

Make the default empty batch command a line of dashes under the 'Actions' header. We can't really do better than that without js.

Conflicts:
	django/website/hid/assets.py
	django/website/hid/views.py
	django/website/media/less/view-edit.less

This is now not returning zero for items that fall outside the range.
This is probably not what we want.

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.)