Merge perfaram/master into beltex/swift2

[perfaram]

Fixes #17 and follows #20

[beltex]

Hi @perfaram!

Thanks for the pull request, its much appreciated, and the first of the project too! :)

This is neat work, but I wanted to take a bit of a different approach. While the underlying mechanism would be using the index selector, wanted to stick to primarily temperature keys only for now. So something like unknownTemperatureKeys() -> [String]. Possibly a allKeys() -> [String] as well, but only returning the FourCC. In addition, I wanted to get some refactoring in first on the Swift 2.0 branch.

Thus, I will not be merging this. However, I’ll note some feedback nonetheless for future reference.

[beltex]

Looks like these got added back in. I removed them because originally, way back, I had thought there should be a :returns: line for each return value, since tuple returns were new to Swift. However, single return line is the convention it seems, independent of the number of values.

[perfaram]

So, thanks for having looked over the modifications even if you didn't mean to merge. Thus, thanks also for the tips.
One more thing : I'll fix some things in my repo and then keep it up-to-date with yours, so that whenever you want to start support for non-temp keys, there will be pieces of code ready (such as value decoding).