Thanks to Julia Lawall for the idea to better parse C+CPP by using
indentation information for heuristic-based parsing. Thanks to Julia
again for many other things too long to enumerate.

Inspiration:
 - C yacc grammar published in 1985 by Jeff Lee:
    lex:  http://www.lysator.liu.se/c/ANSI-C-grammar-l.html
    yacc: http://www.lysator.liu.se/c/ANSI-C-grammar-y.html

 - FrontC of hughes casse ?
 - CIL ?
 - EDG ?