serializable lock consistency patch

I merged the latest version of the serializable lock consistency patch
I could find up to head, and cleaned up some bits of trailing
whitespace, lines over 80 characters, an unused variable that was
producing a warning, and a function that I thought was in the wrong
file.  Context diff attached.

My previous rant on this subject can be found here:

http://archives.postgresql.org/pgsql-hackers/2010-05/msg00792.php

(since I know you all love reading my rants)

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company