Apothecary: Poco Formula iOS (armv7, armv7s, arm64, i386, x86_64)

- Adds formula for iOS compile for Poco for all targeted architectures.

Requires fix for Poco for arm64 :
https://github.com/pocoproject/poco/pull/523
@bakercp you will need to add this to your apothecary tag :D!
Poco Static libs for iOS (armv7, armv7s, arm64, i386, x86_64)
Merge pull request #7 from danoli3/apothecary-poco

Apothecary poco iOS Formula and Fat Libs