Restyle the list of values

- change table based layout to div based (ease the drag 'n drop)
- include the grip
- respect as much as possible the mock-up:
https://tuleap.net/plugins/tracker/?aid=5514

Change-Id: I761843657c7bc777d4ced5576b7b80add2f21ffd
Allow user to reorder the values via drag-n-drop

If the user check the 'alphabetically sort values', then the values are
immediately sorted.
The user can order values as they want (thus disabling the alpha sort)
by dragging the grip of the values.
The order is saved server side when the user submit the form.

Change-Id: I4456cf50b737470f69af74c003de63fa1eb067cc
Merge remote-tracking branch 'gerrit/5514_order_values_of_selectboxes' into tuleap-stable-master

* gerrit/5514_order_values_of_selectboxes:
  Allow user to reorder the values via drag-n-drop
  Restyle the list of values

Change-Id: I4bdec07c2929a1c1362e45d4f880cf313435ed33
Tuleap 6.8.99.9

Change-Id: Id07e3568ffc24075496347895242ba9583c4d07c