Add some additional transitions

I'm going to fork this and start working on some of these, but I thought I'd pass them along to you, too. Might be neat to add an effect option and have some of these in there.

http://tympanus.net/codrops/2013/08/28/transitions-for-off-canvas-navigations/

Review the linked Codrops article and the offCanvasMenu plugin described in the repository to determine which transitions should be supported. Define how an effect option would select them, then verify that the requested transitions work in the plugin's off-canvas navigation behavior.

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