Added ability to drag nested rows within columns
Fixed margins of containers so there is a better overview of parent/child containers when nesting rows/cols
Added sample button label to the custom controls demo page
Added ability to call a filter callback during init and deinit of gm, and refactored code that selects columns.
Fixed bug that repeated the default buttons after previewing or viewing the source code.
Updated the custom controls demo adding the custom filter callback
Added the ability to insert on-demand editable regions that are sortable & removable
Updated the custom controls demo to use the updated src gridmanager.css
Fixed bug that prevented columns from dragging & dropping
Merge branch 'master' of https://github.com/neokoenig/jQuery-gridmanager

Conflicts:
	demo/customcontrols.html
	src/gridmanager.js
Merge pull request #27 from pbreah/master

Feature to add on demand editable regions