DEFS-ARE-CASE-SENSITIVE
* DEFS-ARE-CASE-SENSITIVE ( -- )

accesses CURRENT which is generally the last wordlist that the
DEFINTIONS shall go in. sets there a flag in the vocabulary-definition
so that words are matched case-sensitive.
 example: 
    VOCABULARY MY-VOC  MY-VOC DEFINITIONS DEFS-ARE-CASE-SENSITIVE

useful ordinary primitive