Use motion-support for the string inflector

**This does not pass tests right now, don't merge**

We should probably use motion-support where appropriate, starting with string inflection.

The problem is BW's original `camelize` method actually accepted `true` and `false` as arguments, which the Motion/ActiveSupport variant does not (these only accept `:upper` and `:lower`, which BW also supports).

And because of how BubbleWrap [monkey patches the build order](https://github.com/rubymotion/BubbleWrap/blob/master/lib/bubble-wrap/ext/motion_project_app.rb), if we wanted to write a version of `camelize` which issued a deprecation warning and converted the boolean parameter to the appropriate symbol, it require several changes to the build system. (as I'm understanding it, BubbleWrap will add its own files to the build order first and then insert any other files added to the app afterwards)

so, I think we can:

1. Make changes to the build system and properly deprecate the boolean version of `camelize`
2. Have no deprecation and just break the `true`/`false` version of `camelize` (again, BW already supports `:lower` and `:upper` as arguments)
3. Any other ideas?

cc @tkadauke