Use cpymad.madx directly in cpymad.model
Use cpymad.madx directly in cpymad.model

Since each cpymad.madx.Madx instance now represents one separate
instanciation of the MAD-X library, we can forget about the
multiprocessing wrapper in cpymad.model. The functionality of this part
is replaced by the RPyC service.

Fixes #3 (hopefully).
Fixes #43 for python>=2.7

pymad/cpymad,pymad/jpymad,pymad/jpymad,pymad/jpymad,pymad/cpymad