Improved the setup script and all of the modules, using (auto)pep8 and pyflakes

The source code of IronPyCompiler seems a little difficult to read. One of the reason is that we have not taken [PEP 8](http://legacy.python.org/dev/peps/pep-0008/ "PEP 8 -- Style Guide for Python Code")  into consideration. In these commits I formatted the code with [pep8](https://pypi.python.org/pypi/pep8 "pep8 1.5.7 : Python Package Index") and [autopep8](https://pypi.python.org/pypi/autopep8 "autopep8 1.0.3 : Python Package Index"). At the same time, I removed unused variables and `import` statements, using [pyflakes](https://pypi.python.org/pypi/pyflakes "pyflakes 0.8.1 : Python Package Index").