[plt-scheme] 203.1

The exp-tagged code in CVS for MzScheme and MrEd is now version 203.1.

The changes are minor:

 * Changed `equal?' to compare hash tables by determining whether they
   map the same keys to `equal?' values (where "same keys" is `eq?' or
   `equal?', depending on how the hash table compares keys).

 * Changed `hash-table?' to accept 'weak and/or 'equal and return
   #t only if the first argument is a hash table created with
   the corresponding flag(s).

 * The documentation now clarifies out that `normal-case-path' is
   unlikely to do anything reliably useful, and that it should not be
   used. This procedure will be removed, eventually.

Matthew