Update of the build/testing system

- Reimplemented the build system for tests and test fixtures
  in the same way the building of examples and example harnesses
  is done.
- Added a test case that tests if all configured examples compile
  and link properly.
- Minor update in the configure.py script; with the --build option
  "cmake --build path/to/build/dir" is used as fallback command
  to build the examples, textures, etc.