added support for two new terms: onscreenkeyboard and cursor size, made ...

...some changes to the transformations and fixed all tests

* Added support for two new common terms: on screen keyboard enabled and cursor size
* changed some of the transformations (magnification value can be now a double) and created transformations for the newly supported common terms. Also removed default value in font size.
* Created tests for new common terms and fixed the rest of the tests