Fix side effects with csrf token, add csrf_token to every post form + add ajax (see http://stackoverflow.com/questions/5100539/django-csrf-check-failing-with-an-ajax-post-request), remove django.middleware.csrf.CsrfViewMiddleware ?!

class AbiConverterError(Exception):
    pass

class AbiCommandError(Exception):
    pass

class ToolsConverterError(Exception):
    pass