move h_eq_ptr and h_hash_ptr into datastructures.c / internal.h
quick fix to improve "hashing" of pointers (discard 4 least significant bits)
add (untested) predict set computation
constify read-only hashtable methods
add proper parse table type and lookup function
compile function can't take a const parser
add h_cfgrammar_free()
start filling in h_ll_compile()
finish (untested) LL(1) table generation