[CMake] Synchronize module.

can have time to write on the output stream.

The logger is implemented with a map using __FILE__ and __LINE__.
Using the defaut values means that the same counter is used for
all the streams. This is jeopardizing the test.

Is anyone who tried the tests before ?

[Interpreter] Ignore empty command and Python comments.

remove dg-python binary

to be sure that the current directory is searched

[CMake] details