GENERATORS: Remove useless method Phase()

The phase now has to be memorized by the external wrapper.

Signed-off-by: Gama <misept.dieseneuf@gmail.com>
GENERATORS: Rename and clean ProcessScalar() method

This may actually be considered as a "ProcessParameters" function.
So be it.

Signed-off-by: Gama <misept.dieseneuf@gmail.com>