The support for custom animation wasn't really there, and if you passed the "None" animation option, it still animated. I did all this on master, and figured a pull request was fitting, since you probably don't want your stuff to change underneath you!
Like we discussed, Pilot is now more like your app wide nav controller. You can push/pop view controllers outside of the show model workflow, which I have had to use. I was using custom animations, but now I'm not, so I just pulled that out.
Removed support for custom animations until we have a solid workflow.…
… Switched language around a bit to match Apple defaults. Added view controller pop.