OS and OSVersion

This fork adds the ability to get the OS and OS Version from the user agent (for now, only works for iOS and Android devices).

I chose to create a separate JSON file to store the OS-related info so that it would be easier to update the Mobile_Detect JSON which is a separate project in itself.

I will keep maintaining the OS version file in the fork and create pull requests when other OS detections are added.

TODO: Create tests.