Bug 22408: Subscription entry form cleanup

Bug 22408: Subscription entry form cleanup

This patch makes a number of changes to the subscription entry form:

  - Make the default layout single-column.
  - Switch the layout to two-column only when testing prediction
    pattern.
    - Add a button to hide the prediction pattern test pane.
  - Change the style of some buttons and links. Add Font Awesome icons
    to some.
  - Clean up some issues with capitalization and spacing.
  - Make it clearer when form fields are read-only: Move "locked" form
    field style from addbiblio.css to staff-global.css and improve it
    with regard to mouse interactions

To test, apply the patch and regenerate the staff client CSS. Clear your
browser cache if necessary.

 - Go to Serials -> New subscription.
 - Readonly fields under "Vendor" and "Record" should show a small
   padlock icon.
 - Test the process of adding a subscription, paying special attention
   to the advanced pattern controls: Showing, hiding, modifying,
   canceling.
 - Test the process of editing a subscription in the same way.

Signed-off-by: Michal Denar <black23@gmail.com>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>