Fixed numerous issues in pyro.sort_tree

Fixed numerous issues in pyro.sort_tree, including:
- user defined classes (like 'no-nest') were being removed
- wrong icons were being set for all parents when dragging items with hidden children
- child icons didn't properly update when dragging/dropping items with children
- cookies weren't saved when dragging/dropping items
- cookies could save invalid states
Update details.php
No need to make users_groups in details.php
Incorrectly referenced FieldUi.php
Closes #3227: Increase Password Length
20 was way too low. The 2.3 branch uses bcrypt which has a 72 character upper limit. To avoid silly issues when switching from bcrypt to "mystery future thing" I've set the limit to the somewhat arbitrary value of 50.

This may just be punting the "minimum is too low" issue down the road a bit, but the chances of people being sad about 50 being to low is much less likely than people being upset about 20 being too low.
Merge branch '2.3/develop' of git://github.com/pyrocms/pyrocms into 2.3/develop
Merge pull request #3173 from Vaporizer8/2.3/develop

Boomskie
Boom
Merge branch '2.3/develop' of github.com:pyrocms/pyrocms into 2.3/develop
Merge branch 'refs/heads/2.3/develop' into 3.0/develop

Conflicts:
	system/cms/themes/pyrocms/js/scripts.js