Tests with deep_reload
tests benefits from a deep_reload of the pyFAI module, allowing
re-build and test in a single run like "python test_all.py -f"

The -r option has been added to clean the repository previous to the
build.

With test_all many tests are not working due to remaining inhertience
issues.
Simplified version of deep_reload for tests
copy openCL files when needed
Merge remote branch 'origin/master'