Rewrote translate() as follows:
- 'delete' is a C++ keyword; use 'del_table' instead
- apply Py_CHARMASK() to del_table[i] before using it as an index
*** this fixes a bug that was just reported on the list ***
- if the translation didn't make any changes, INCREF and return
the original string
- when del_table is empty or omitted, don't copy the translation
table to a table of ints (should be a bit faster)
Rewrote maketrans() to avoid copying the table (2-3% faster).