pgsql: Fix relcache init file invalidation during Hot Standby for the

Log Message:
-----------
Fix relcache init file invalidation during Hot Standby for the case
where a database has a non-default tablespaceid. Pass thru MyDatabaseId
and MyDatabaseTableSpace to allow file path to be re-created in
standby and correct invalidation to take place in all cases.
Update and rework xact_commit_desc() debug messages.
Bug report from Tom by code inspection. Fix by me.

Modified Files:
--------------
pgsql/src/backend/access/transam:
xact.c (r1.284 -> r1.285)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.284&r2=1.285)
pgsql/src/backend/utils/cache:
inval.c (r1.95 -> r1.96)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/inval.c?r1=1.95&r2=1.96)
pgsql/src/include/access:
xact.h (r1.101 -> r1.102)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/access/xact.h?r1=1.101&r2=1.102)
pgsql/src/include/storage:
sinval.h (r1.57 -> r1.58)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/sinval.h?r1=1.57&r2=1.58)