Bug 19497: Removed title (tooltip) from Edit button in items_search_fields.tt

Bug 19497: Removed title (tooltip) from Edit button in items_search_fields.tt

This patch removes the tooltip that appears when hovering over the Edit button
of Item Search Fields in the staff client. This was done for consistency reasons,
including that this tooltip is not translated and tooltips do not appear to be
on the majority of buttons in the staff client.

Test plan:
1) In Home->Administration->Item search fields create a new search field
if you haven't got any already
2) Observe the tooltip that appears when hovering over the Edit button in
the Item serach fields table.
3) Apply the patch and observe that the tool tip no longer appears.

Sponsored-by: Catalyst IT
Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>