Refactoring

I have refactored the sources to reduce the amount of needed memory and time to create the output files and run the tests. The changes were inspired by zieges changes in the browsap-php class, but I dont use generators.

To make this possible the following changes had to made in the json resources:
1. The 2 core files are moved to outside of the useragents folder. They are added to the datasource object with their own setter now. With this we do not need to check if we are handling actually the core files.
2. Each `userAgent` section has to include all properties who are changed from the default properties, even the section inherites from another section. This makes it possible to handle each `userAgent` section by its own without searching its parents.