Resolve rare duplicate URL Alias Bug

On a few open cart websites we have worked on, sometimes there is a duplicate url_alias entry for a category.
This change resolves the issue when editing the category again.
Merge pull request #673 from JeramyMywork/patch-1

Resolve rare duplicate URL Alias Bug
committing the unfinished work of the admin dashboard
added status and sort order to the modification manager
more modification work done
updated font awesome to the latest
updated icons in page titles and more work done on the extension installer
more extension installer code added
more extension installer work done
updating of the image editing system
more work on the auto installer done
added loading image when customer click on Confirm Order button, allow user have some feedback / response after click.
more extension installer work done!
added try catch for error management
Missing User Group model Necessary function

There was no removePermission function, and its very necessary when uninstalling a module.
more installer work done
more extension work done
more extension installer work done!
updated the buttons admin form buttons to use correct html and not javascript hacks.
list options by it's sort order