webclient: Precat checkouts force a circ modifier

[Kathy Lussier]

The web client does not allow a precat checkout with an "Unset" circulation modifier as is currently possible in the xul client.

Some systems do not use circulation modifiers for all of their materials and will need the ability to add a precat without a circulation modifier. Also, this menu should default to the Unset option.

[Kyle Huckins (khuckins)]

I've put a commit up here: http://git.evergreen-ils.org/?p=working/Evergreen.git;a=commit;h=60a41963d18c9732f8c43d48ecf35bce30763789

It was originally coded to default to the first possible circ modifier, so this was a matter of making sure there would be an option that would keep the circ modifier as null, and dropping the default setting.

[Kyle Huckins (khuckins)]

I realised I linked to the commit here, rather than the branch itself - http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/khuckins/lp1537217-precat-checkouts-modifier

I amended the commit to be a bit more useful, as it was written less with a testing user in mind, and more with a developer in mind. This should be a bit more readable.

[Christine Burns (christine-burns)]

tested on https://mlnc3.noblenet.org/eg/staff/

I have tested this code and consent to signing off on it with my name, [Christine Burns] and my email address, <email address hidden>.

[Kathy Lussier (klussier)]

Thank you Kyle and Christine! Merged to master and backported to release 2.10 and 2.11.