[Tests] : add CMakeAS7-TestProjects as a reference in CMakeAS7 repo and use it as part of integration testing plans.

[bebenlebricolo]

Enable integration testing using CMakeAS7-TestProjects repository in order to validate that the codebase is stable (costy solution but will help raise problems)

0. Add CMakeAS7-TestProjects as a submodule.
1. Prevent CMake to perform a tryCompile, we don't want to install AtmelStudio7.0 nor its derivatives on the testing maching in order to validate that a project is valid
2. Implement quality criterions for each test in order to inspect generated files and their content.