move tests to src/test dir and subdirs

- The tests are now all gathered in :
test/triqs : for the C++ libs
test/pytriqs : for the python part
test/speed : little speed check program whch are compiled,
but for which test are NOT enabled (would take too long).

Additional cleaning & additions :

- arrays : clean test. python_stuff gone (was empty)
- added optional automatic Valgrind test for pure C++ code.
- made some names more explicit, specially for speed test.
remove injector

- not needed since we don't use boost python any more

	deleted:    pytriqs/base/utility/injector.py