* Adding used types list of code-obj so we know every type used in a
  program to easily identify structs. CUrrent his is messing about as
  labels within labels seem to eat the list.. dont know why yet.
* signaures added to final output
* types not have a post initialise method they can hook onto.
* type-nam now works for arrays .. .thsi needs to be renamesd to
  typr->typespec