* main_codequery.ml: support for C via graph_code and hook
improved in_assign also in graph_code_c
* main_scheck.ml: remove cpp_identifier fp heuristic for C, no need! we
are actually more robust than clang now
* lang_c/analyze/graph_code_c.mli: prolog hook!
* lang_css/parsing/ast_css.ml: remove dead type
* lang_lisp/analyze/graph_code_lisp.ml: misc