pgsql: Support EEEE (scientific notation) in to_char().

Log Message:
-----------
Support EEEE (scientific notation) in to_char().

Pavel Stehule, Brendan Jurd

Modified Files:
--------------
pgsql/doc/src/sgml:
func.sgml (r1.485 -> r1.486)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml?r1=1.485&r2=1.486)
pgsql/src/backend/utils/adt:
formatting.c (r1.159 -> r1.160)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/formatting.c?r1=1.159&r2=1.160)
numeric.c (r1.118 -> r1.119)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/numeric.c?r1=1.118&r2=1.119)
pgsql/src/include/utils:
numeric.h (r1.27 -> r1.28)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/numeric.h?r1=1.27&r2=1.28)
pgsql/src/test/regress/expected:
numeric.out (r1.24 -> r1.25)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/numeric.out?r1=1.24&r2=1.25)
pgsql/src/test/regress/sql:
numeric.sql (r1.15 -> r1.16)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/numeric.sql?r1=1.15&r2=1.16)