switch token to use statically allocated memory only
split atom token into symbol and literal
switch literal type to signed int64
bugfix in node_print_recursive to handle NULL node input
minor comment update in lambda_bind
add "shorthand" style node print
split dlist.h into dlist.h and dlist.c, get rid of some unused code
update node_print_pretty to use list shorthand, update node_gc_print_state()
add wrapper functions for memcell_t.locked and memcell_t.refcount
update TODO
actually add new dlist.c source file...