Bug 35087: (follow-up) Accept only values which will be saved correctly

Bug 35087: (follow-up) Accept only values which will be saved correctly

This patch adds a regex (thanks to Katrin for the help) specific to the
range of values which will be accepted by the discount column in the
database which has the type "float(6,4)".

The patch also removes the format() filter from the template so that
values returned from the database won't be truncated:

Using "format ('%.1f')", a value in the db of '9.009' would appear in
the edit form as '9.0', a change which could be missed if the user was
editing some other field in the vendor edit form.

To test, apply the patch and clear your browser cache if necessary.

- Go to Acquisitions -> Vendors -> Edit vendor.
- Under "Ordering information," test entering various values in the
  "Discount" field. It should accept numbers with up to two digits
   before the decimal and up to three digits after the decimal:

   9, 99, -99, 99.9, 0.99, 99.99, 99.999

- In each of these cases, confirm that a value accepted by the
  client-side validation is also accepted when you submit the form and
  is correctly displayed when you edit that vendor again.

- It should not accept:

   100, 100.001, 100.00001

- The error message has been updated to read, "Please enter a decimal
  number in the format: 0.0"

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Sonia <sonia.bouis@univ-lyon3.fr>
Signed-off-by: Olivier V <olivier.vezina@inLibro.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>