added RealmSwiftExamples.xcodeproj

Due to a bug in Xcode6-Beta3, using a Swift framework from outside the xcode project that created it is [quite a complex process](https://github.com/realm/realm.io/wiki/Realm-Swift-Installation).

So I'd like us to consider using a temporary xcode project like the one included in this PR to contain all our Swift examples alongside a framework target. Given the severity of this bug, I'd expect Apple to fix it for the next Xcode beta, likely to be released on July 21st. So this is quite temporary.

But at least, it would allow us to continue working on the Swift examples. Thoughts? @kneth @emanuelez @alazier?

BTW, if someone wants to move the xcodeproj to `examples/swift` from root, please feel free to go and do that on this branch. I'll be sleeping now :).