Make SQLiteCipher's dependencies come in through cocoapods, and therefore resolve all of the build issues

[gblotter]

Instead of having this repo pull in SQLite.swift as a submodule, I removed all of those dependencies and instead created a pod file that pulls in SQLite.swift and SQLCipher and handles all of linking for us.

This branch compiles as is, but that is because it's pointing to my fork of SQLite.swift. I'm waiting for a PR to be accepted on the SQLite.swift repository. The change is a single word - public - in front of the check() function in the Connection.swift class.

Pending that pull request being approved, I can then lint a pod spec that I have prepared for this repository that should get it up and running again as a fully functioning cocoa pod.

This should solve: #10, #1, #8, #5, #3, and probably #7 as well.

Please let me know if you have any questions or suggestions!