JSON Class Generator versions

v1.1 [Jan 15, 2019]
- app
- shows a toast when export is done
- saved files have new format (version 1.0.0 will not be able to open them after saving with 1.1.0 or later versions)
- generated code
- passes analysers: fbinfer, FauxPas, Apple's static analyser
- is warning-free
- makes use of nullability annotations and Objective-C generics where possible
- contains a speed improvement
- bugs fixed
- the background color of a cell does not turn black in rare occasions