Clean project

most of the changes are inspired by django
https://github.com/django/django

.gitignore :
    - ignore sublimetext files
    - dont ignore 'bin', it can be usefull for put executable python script (source code so part of the repo)

MANIFEST.in :
    - cleaner and more explicit (grabed from django)

 `gooey/__init__.py` :
    - add `__version__` for refere to it anywhere in the project but write it one time (used in setup.py and perhaps in an hypothetical  'gooey --version' executable ( saw this in a few big project)
    - put import into try except for python 3 developpement of new feature
todo : wx should be optional for python 3 compatibility, tkinter should be the default, with optional support for pyqt, pyside, wx, pygtk etc ... if someone want to do them (i will probably do tkinter)

`gooey/languages/__init__.py`:
    - ? :)

setup.py:
    - django copied

test.py :
    - better to have a tests directory instead