Update Swift code for Xcode 6 beta 3

- Use new array syntax
- Use new dictionary sugar where possible (encountered some compiler
  errors for some dictionaries)
- Fix build errors around dictionaries

Fixes issue #93.
Use array initializer syntax

Use Swift's array initializer syntax (see "The Swift Programming
Language", page 145) to initialize empty arrays using type inference.

Typealiases for closures also necessary to prevent compile errors
(reason unclear, but arguably improves readability, too).
Merge pull request #94 from modocache/issue-93-xcode-6-b3-support

Update Swift code for Xcode 6 beta 3