Clean up for cxxgen
Merge pull request #52 from pbrunet/master

Clean up for cxxgen.py
Rework pass manager interface

* Un-spaghettify class hierarchy
* rework API as a combination of `prepare' and run

`prepare' gathers analysis dependencies
`run' performs the transformation

to add more preparation, overload prepare
to add post-processing, overload run
Sanitize cxx type handling

* Remove obsolete/unused code
* Use a generic type builder for all types
* Cleaner class hierarchy
* Add doctest / docstring accordingly
More code cleaning

* docstring for a few more analysis
* less obfuscated code
Fix bug in Globals

The __builtin__ module is obviously always preloaded...
PEP8 compliancy
Adding file support based on C FILEs.
Needs reimplementation of core::string to insure better performances.