Squashed commit of the following:

Squashed commit of the following:

commit 7b6b0bdf21bca0856bfefc1859618e6e36b35d25
Author: John Benediktsson <mrjbq7@gmail.com>
Date:   Mon Sep 26 21:09:07 2011 -0700

    hashtables.wrapped: cleanup common prettyprint code.

commit aaed81f93dcfa295bd3dfd8102a5c39511209934
Author: John Benediktsson <mrjbq7@gmail.com>
Date:   Sun Sep 25 15:58:55 2011 -0700

    hashtables.wrapped: cleaner >foo-hashtable.

commit bb0f8379480935d1dcf482170e8e2a4a519d81d3
Author: John Benediktsson <mrjbq7@gmail.com>
Date:   Sun Sep 25 15:39:41 2011 -0700

    hashtables.identity: migrate to use hashtables.wrapped.

commit 2e71b3324f0803c15a55429acddc13f06b4876ae
Author: John Benediktsson <mrjbq7@gmail.com>
Date:   Sun Sep 25 15:39:19 2011 -0700

    hashtables.sequences: wrapped hashtable that uses "sequence=" for key comparison.

commit 040f33b40c424887d596af5c3bd9de0eef9a682e
Author: John Benediktsson <mrjbq7@gmail.com>
Date:   Sun Sep 25 15:39:05 2011 -0700

    hashtables.wrapped: base class for "wrapped hashtables".