added valgrind python suppression file

To start a valgrind memory check use the following command:
  valgrind -v --leak-check=full --suppressions=misc/valgrind-python.supp python -E -tt ./setup.py test

If your python installation is not compiled with valgrind option, you get as well tons of false-positive leaks
in valgrind. Just check for git_* function the the output. Have in my that circular memory dependencies can
 not easily be found with this approach.
added missing remote header file and fixed instance creation