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.
Update Swift examples
Build with Xcode6 beta 5
Merge pull request #734 from realm/tg-beta5

Update Swift code for Xcode 6 beta 5
Add a test for memory leaks when creating a lot of queries
Fix the memory leak when creating queries
Add an explanatory comment