Create, and open recipe overrides using contextual menu in Recipe Table View 

You should be able to right click or control click on the recipe in the table view and be presented with a menu.

Setting the editor now uses Launch Service to register the app, so that the xxx.xx.recipe file will be opened by the specified app even back in finder.

The NSTableView is now subclassed with LGTableView which intercepts the mouse click event.
It's also wired up to do something, someday with LGPopularRepos, what ever that may be.

The table column identifiers were renamed from appCheckbox/appName to recipeCheckbox/recipeName.
The table column cell is no longer "selectable" as @homebysix  pointed out, it makes it look editable.
This was also done in the repo table view.

(This PR should probably be brought in after the casper-love-touchup branch)