after all that's the whole point of bitvectors
some prettyprinting tweaks
more uniform way to handle forwarding pointers. fix forwarding
of gensyms
:keyword symbols
fixnums still have 30 bits
moving towards making "guest functions" more opaque; their type is now
just 'builtin
pretty printing some forms better: defun, defmacro, for, label
support *print-pretty*