2.2.2: Moving beyond libffi

Posting as a PR for review.

Unit testing verified:
 - [*] Mac x86_64 (10.9)
 - [*] `x86_64` iOS simulator (7.1)
 - [*] `i386` iOS simulator (7.1)
 - [*] `arm64` (7.1)
 - [ ] `armv7s` (7.1)
 - [ ] `armv7` (7.1)

Manual testing verified:
 - [ ] Mac x86_64 (10.8)
 - [ ] `i386` iOS simulator (6.1)
 - [ ] `armv7s` (6.1)
 - [ ] `armv7` (6.1)