* h_program-lang/layer_graph_code.ml: new file, just macrolevel for now
* h_program-lang/graph_code.ml: file_of_node raise an exception now
* lang_ml/analyze/graph_code_cmt.ml: use readable path
* code_map/style2.ml:
* h_program-lang/layer_code.ml: fix heatmap, better for bottom up layering
* h_program-lang/layer_graph_code.ml: microlevel
* h_program-lang/graph_code.mli:
* main_codegraph.ml: -gen_bottomup_layer