Fork, and some general improvements

[peterix]

I included your code here: https://github.com/MultiMC/MultiMC5/tree/develop/libraries/ganalytics

Some changes I made include:

• Refactoring into more parts.
• Replacement of the Qt OS detection with something that works when you use an old Qt version (I did not care about iOS or Android, so they are not included).
• User agent strings the library generated did not work with GA at all - there was no OS version. So I just ripped that part out and started using custom dimensions... This is probably related to #6
• CMake build system.
• Support for IP anonymization (&aip=1)
• Application is responsible for generation and storage of client IDs
• Elimination of QSettings (My application is not using QSettings, I think it's bad form to force its use)

I can turn these into pull requests, but I'd rather ask first which of those changes would be interesting to you.

[MKV21]

Sounds good to me, could you turn your copy into a fork? We might be interested in the pull requests for the refractoring and ip anonymization, but it would be easier to have a look at them once submitted. The other things would probably break existing projects using this stuff, but we could take a look nevertheless.