Support for Swift 3.0

[netgfx]

More specifically Swift 3.0 and Carthage support.

[alexkaessner]

@khawars At least Swift 2.3 support would be awesome! 👍 Otherwise Xcode 8 has a problem to build it.

The only errors Xcode shows are these. Should be easy to fix:

[khawars]

@netgfx and @alexkaessner I am back on the earth for a couple of days :) I'll try to fix as many issues as possible and will try to add support of Swift 3.0

[alexkaessner]

@khawars Nice and thanks! Maybe you should first do a small Swift 2.3 update before you move on to Swift 3. So we can still use the framework (with an older release) if we don't want to update to Swift 3 yet.

[mspasov]

@alexkaessner , @khawars I just did #57, should work under swift 2.2 and 2.3. Untested :)

[khawars]

Updated with Swift 2.3 and 3.0.
User master branch for Swift 3.0, and develop/swift2.3 for 2.3. Please reopen for any related issue.