Update Swift code for Xcode 6 beta 5

Mostly mundane tweaks for changes to Swift. The two big ones are that swift's
name mangling is now just "module.classname" and that all properties have to be
explicitly declared as `dynamic`.

Closes #733.
That'd make it difficult to write anything which uses the class name for a class which can be defined in multiple targets. For example, all of our Swift tests use classes like iOS_Tests.SwiftCompanyObject when testing for iOS, but the same class is named OSX_Tests.SwiftCompanyObject when running OS X tests.

All of the code should probably support fully-qualified names in addition to the bare classname, though.