Mark and return false for clicks on disabled colors #6

Here is a solution proposal for issue #6 - Handle disabled options.
My suggestion is to mark disabled colors with a &times; symbol.
Upon click, simply return false, keeping the chooser open.
Further, the mouse cursor changes to not-allowed on mouseover.
revert spacing back to original 4 spaces
reduce disabled css to only cursor & border changes
Merge branch 'master' of https://github.com/dotJoel/jquery-simplecolorpicker
Refactoring
Remove role="button" and tabindex="0" if the color is disabled
Replace selected class by data-selected

=> symmetric with data-disabled
Fix CSS when the selected option is also disabled
Increase timeouts
Fix line-height
Add themes