Bug 10678 - Allow framework selection when creating from Z39.50

If we are creating a new record, we are forced to use the default framework
and then change it after we have the cataloguing form filled. This patch
adds the option to choose (from a splitted button dropdown) which framework
to use.

To test:
- Apply the patch.
- Go to More > Cataloguing
- Check there's a nice split button that says "New from Z39.50"
a) Click the button, the usual Z39.50 search popup should appear and work as expected
   (check the URL parameters and see frameworkcode= has no value
b) Click on the dropdown arrow, choose a framework and the usual Z39.50 search popup should
   appear, this time frameworkcode= should have the chosen value.

Edit: fixed a small bug that prevented the default framework to be called. Thanks Owen for testing.

Sponsored-by: Universidad Nacional de Cordoba
Signed-off-by: Melia Meggs <melia@bywatersolutions.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Notes on second patch.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Bug 10678 - Update addbooks help page

The button's name changed, and a caret was added.

Sponsored-by: Universidad Nacional de Cordoba
Signed-off-by: Melia Meggs <melia@bywatersolutions.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Passes all tests and QA script.
If you click the button directly, the default framework is still used.
If you use the split button functionality to select another framework,
this framework will be used for the imported record.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>