Stops event propegation when pressing the remove slide button
JSDoc comments, indentation and tiny bits of refactoring.
Added multidrag + undo to slides in overview mode.
Included selectables into jQuery UI custom build.
Added rectangle selection to operating table and overview mode.
Merge pull request #212 from neochief/multidrag-overview2

Multidrag for transitions editor. Rectangle selector.
Updated multisortable to use ui-selected GH-212
Re-added the fix for the outline rendering bug in Firefox
Added a border for when the slide is rotate at a 90 degree angle to the
viewport

This prevents the slide from becoming invisible since the border that
reflects the un-rotated position of the slide remains present.