Add Python (2.x) and (partial) CoffeeScript support

As per the advice in #2 (thanks for the heads up) I have added keywords to the blacklist for Python (2.x) and CoffeeScript.  I think it's good enough to go for now, but there are a couple of things that I've not been able to get fully working...

 * In CoffeeScript, object member variables are prefixed by @. For some reason these are not being touched by semantic-highlight.
 * There's a similar thing with Python with decorators, where you may have a [decorator](https://docs.python.org/2/whatsnew/2.4.html#pep-318-decorators-for-functions-and-methods) called `@app` (for example) and a variable called `app` and they are actually the same variable (though the one beginning with @ is not highlighted.
 * In Python 3 print is a function, not a keyword.  I don't think this is a huge problem.

Let me know if this needs any further work.

Incidentally: how do yo test these things when they are in development?  I was pushing to my fork and using Vundle to install/update it, but this gets quite tedious when I am making mistakes in the coding ;-).  In this case I used `git push -f` to cover them up :-) but I wonder if it's possible to 'install' an in-development version just by making a symlink or something?