pgsql: Done: < o Remove per-backend parameter file and move into shared

Log Message:
-----------
Done:
< o Remove per-backend parameter file and move into shared memory

Add for Win32:

o Allow the shared memory address to be configured via GUC

Modified Files:
--------------
pgsql/doc:
TODO (r1.1420 -> r1.1421)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1420&amp;r2=1.1421)