Added draggableCancel.

Fixed some placement inconsistencies while RGL is mounting, with css transforms and percentages....

Allow passing cancel handle for react-draggable

Use react directly and require addon modules explicitly

Any properties set directly on a grid item will now override any global settings.

Allow each grid item to define whether or not it is draggable/resizable.

Adds a note about using custom keys

If you do not use the index for a grid item key, then the layout cannot be found. You can expli...

This means it won't have to stay in sync when we add new grid item properties
from now on. This ...

This gives us about 6x more paint performance.

Option is controlled via 'useCSSTransforms'.

The issue was caused by two factors:

1. When multiple collisions occur, they are processed one ...

Example 6: Dynamic add/remove of elements
Example 7: LocalStorage sync

Should be a bit faster and more accurate. Hopefully a lot less
bizarre sorting swaps in the future.

This is required because the runtime tries to export to the window rather than
return the runtim...

If this is badly specified, we can enter an infinite loop. I'd rather check it once on init
than...

Moving to for loops in some critical sections helps performance significantly.