Add iOS unit tests, replace unit test dependencies with cocoapods, fix iOS build errors

Lots of changes in this one.

Moved the unit test target out into a separate xcode project, which is included in a workspace, alongside a separate project for building the OS X static library. Added an iOS unit test target. Now using cocoapods to provide the OCHamcrest and OCMockito dependencies for the unit test targets. In addition, we use cocoapods to link the library into the unit tests, instead of manually compiling the necessary sources into the unit test bundle. Doing all this revealed a problem: `isEqualTo:` doesn't exist on iOS. This was easily fixed by changing `isEqualTo:` to `isEqual:`, which is present on both platforms. As near as I can gather isEqualTo: exists for use by components interfacing with applescript, so this shouldn't present a problem. See http://stackoverflow.com/questions/7096691/difference-between-isequalto-and-isequal and http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Protocols/NSComparisonMethods_Protocol/Reference/Reference.html.

There are four unit tests that are currently failing on iOS, but still passing on OS X. All are found in TyphoonTypeDescriptorTests. On iOS, instead of TyphoonPrimitiveTypeUnsignedLongLong we get TyphoonPrimitiveTypeInt and instead of TyphoonPrimitiveTypeLongLong we get TyphoonPrimitiveTypeLong.

Let me know your thoughts!