Change DICT_FIND to DICT_FIND_{REF,VAL}

- In many places, DICT_FIND was awkward to use, as it required the use
  of pointers even in cases that the dictionary already stored
  pointers.  For those cases, add DICT_FIND_VAL.

- Rename the original DICT_FIND to DICT_FIND_REF to make the
  disctinction clear.  That is useful if the dictionary holds actual
  structures.
7 files changed