S expression-serpent

[Probably a bit of a waste of time](https://duckduckgo.com/html/?q=s%20expression%20parser%20python), i dont want to waste yours, feel free to click 'close'. Do feel i found a bug in Python 3.4.0 though.. I reckon it is one that should have been detected by their tests and not have been sent downstream. (dont they fuzz test..)

`s_expression_parse` and `s_expression_parse_stream` output can be used in place of `parser.parse` output.

Note that some of the modifications i made, where some of the `numberize` functionality was extracted from `compiler.py`, when i needed it [for cll output](https://github.com/o-jasper/serpent/tree/to_cll)(unfinished, not sure if i should continue edit: wait.. that **should be to_LLL!**) got into it, i can fix that back if you want.

I havent plugged it in the main serpent program.. To be honest i dont see how it works.. It reads the source code and some of the functions are directly turned into serpent commands?

Something like `serpent compile_to_assembly 'x = 5'` doesnt work for me.. Python3 doesnt do `print ...`, just as a regular function. How do i run it without running the install script? Mucked with `PYTHONPATH`, but no luck. I often have to run stuff with python2 instead of what the program itself suggests, i think that is essentially the problem that people dont recognize they're still using python2?