Allow objects such as images, strings, and audio clips to display rich representations of themselves in the inspector by providing methods for a content-gadget generic.
C: now sets the stack effect of the new word to slot names
add new basis/constants vocab; CONSTANT: foo bar is equivalent to : foo bar ; inline
(going to fold CONSTANT:, ALIAS: and qualified into core soon perhaps)
tighten the screws: inline words now need a stack declaration too
update some usages of inline words