pgsql: Fix storage size for btree_gist interval indexes.

Log Message:
-----------
Fix storage size for btree_gist interval indexes.  Fix penalty
calculations for interval and time/timetz to behave sanely for both
integer and float timestamps; up to now I think it's been doing
something pretty strange...

Modified Files:
--------------
    pgsql/contrib/btree_gist:
        btree_gist.sql.in (r1.12 -> r1.13)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/btree_gist/btree_gist.sql.in.diff?r1=1.12&r2=1.13)
        btree_interval.c (r1.5 -> r1.6)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/btree_gist/btree_interval.c.diff?r1=1.5&r2=1.6)
        btree_time.c (r1.8 -> r1.9)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/btree_gist/btree_time.c.diff?r1=1.8&r2=1.9)
        btree_utils_num.h (r1.4 -> r1.5)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/btree_gist/btree_utils_num.h.diff?r1=1.4&r2=1.5)
    pgsql/contrib/btree_gist/expected:
        init.out (r1.1 -> r1.2)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/btree_gist/expected/init.out.diff?r1=1.1&r2=1.2)