fix dependency check.
fixed vec_shape, chain ref counting.
env_bind retain fix.
replaced ref_len with data_len, vec_len.
use strnlen.
fix host_init; use obj_is_vec_ref; env assertions.
use SYM_LIST x macro; reorder syms.
reordered Mem fields.
VEC form.
fn vectors now have is-macro field; renamed "perform" to "raw", and changed syntax.
Set type.