Minor bug fix release

v3.1.1

Release 3.1.1

v3.1.0: Merge pull request #1 from maximalink/optgroup

Optgroup

First release after forking

New sortable_tree features:

• Inline add new item feature (ajax request)
• Inline edit items (ajax request)
• Delete items using ajax request
• It works in subtree using :parent_id param

Improvements in source:

• Reorganized source files
• Code refactoring
• Code DRYing