Better examples of DAGs generated by GGEN.
Removed old example.
Has became useless.
New Makefile.
Lexer + Parser for GGEN graphs.
The parser+lexer are working :).
Slight correction in the parser: when a node is not part of any edge, ggen writes "id;".

Makefile now takes ocamlbuild.
Should be good to go for the first tests.