The persistent key implementation will be split across multiple
files as it will eventually be implementing multiple storage
backends. As these internal functions will need to be callable by
other files, we will add the headers in the library folder. This
commit adds this include location to the necessary scripts.
For tests, the library is added as an include location as testing
on-target with Mbed OS is not possible with paths including ".."
Add a function that deletes all the old Visual Studio prokect files
before generating the new ones. This ensure that project files for
delete example applications are removed from the repository.
