cfront v3

This is a project for a self education and historical research of the C++ compiler.

A cfront compiler can help to get a concrete understanding how vtbls, class objects and so on really look like.

Additionally cfront can provide a useful platform to compile historic C++ programs.

PS: a sources was taken from the cfront re-port for the 4th edition of plan9 http://plan9.bell-labs.com/sources/extra/c++.2e.tgz http://9p.io/sources/contrib/john/package/packages/cfront.iso.bz2 http://www.quintile.net/plan9/c++/c++src.tbz

PPS: features not implement in cfront 3.x

Support for the `volatile' keyword.
Support for the `signed' keyword.
Support for wide character literals.
Support for wide character strings.
Exceptions.
- Support for the `long long` type (done)