Reuses a dictionary for the hash table to reduce the string compare
costs. Not worth it unless validating big DTDs
without with
db10000 tree 175/79 179/81
db100000 stream 1222 1217
dba100000stream 593 601
REC validation 1986 2098
Docbook valid 10808 10649
Tue Feb 24 19:09:49 CET 2004