allow ui-tree to be a target
Merge pull request #220 from gilluminate/master

Allow ui-tree to be a target
Don't bound the right side of the dragged element to the right boundary
Instead, bound the left side of the dragged element
Begin the implementation of stickiness parameter
To do so, change the way we detect the target. Now calculate intersection
with nodes element instead of getting the closest elment.
Update attributes retrieval
Remove npm warnings

Added `description` and `repository` in the `package.json` file.
Merge pull request #221 from bobey/remove-npm-warnings

Remove npm warnings by adding ```description``` and ```repository``` in the ```package.json``` file
Added JSCS to enforce coding style

In order to harmonize coding style hover differents commits and pull requests.
Remove coding style errors

Source code now respects coding style check with jscs AND jshint.
Added jscs and jshint checks into `grunt test` task
Merge pull request #222 from bobey/enforce-coding-style

Enforce coding style
Issue #216: rewrite intersection detection

The intersection between dragged element and overlapped element is now
configurable.

Use the parameter "coverage". Can accept an integer between -100 and 100.
Negative number indicates that it's the top border that is used when going
down (and the bottom one when going up). Positive number indicate that it's
the bottom border that is used when going down (and the top one when going
up). And the number is the percentage of coverage of the element before
detecting the overlapping.
Merge branch 'issue/216'
Enforce JSCS code style and clean/format code
Fix connected trees with the new overlapping detection
Dirty support of the horizontal mode
Should be rewritten cleaner
#228: Add droppedInto callback.
This event fires from the receiving tree
Check if node isn't collapsed before trying to move as a child
#210: add the ability to expand a node when hovering

Simply add "expand-on-hover" attribute which can be a boolean (true: expand
immediatly on hover, false: don't expand on hover) or a number (0: expand
immediatly, >0: wait for this milliseconds to expand).

Events are triggered on timeout start (expandTimeoutStart), cancel
(expandTimeoutCancel) and end (expandTimeoutEnd).
Move the element on change of tree.
This avoid to have to move the element up or down when going to an other
tree. The element will move on the new tree to the right position according
to it's vertical position.