pgsql: Adjust input routines for float4, float8 and oid to reject the

Log Message:
-----------
Adjust input routines for float4, float8 and oid to reject the empty string
as valid input (it was previously treated as 0). This input was deprecated
in 8.0 (and a warning was emitted). Regression tests updated.

Modified Files:
--------------
    pgsql/src/backend/utils/adt:
        float.c (r1.112 -> r1.113)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/float.c.diff?r1=1.112&r2=1.113)
        oid.c (r1.60 -> r1.61)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/oid.c.diff?r1=1.60&r2=1.61)
    pgsql/src/test/regress/expected:
        float4-exp-three-digits.out (r1.5 -> r1.6)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/float4-exp-three-digits.out.diff?r1=1.5&r2=1.6)
        float4.out (r1.11 -> r1.12)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/float4.out.diff?r1=1.11&r2=1.12)
        float8-exp-three-digits-win32.out (r1.4 -> r1.5)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/float8-exp-three-digits-win32.out.diff?r1=1.4&r2=1.5)
        float8-exp-three-digits.out (r1.9 -> r1.10)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/float8-exp-three-digits.out.diff?r1=1.9&r2=1.10)
        float8-small-is-zero.out (r1.7 -> r1.8)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/float8-small-is-zero.out.diff?r1=1.7&r2=1.8)
        float8-small-is-zero_1.out (r1.1 -> r1.2)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/float8-small-is-zero_1.out.diff?r1=1.1&r2=1.2)
        float8.out (r1.21 -> r1.22)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/float8.out.diff?r1=1.21&r2=1.22)
        oid.out (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/oid.out.diff?r1=1.10&r2=1.11)
    pgsql/src/test/regress/sql:
        float4.sql (r1.6 -> r1.7)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/float4.sql.diff?r1=1.6&r2=1.7)
        float8.sql (r1.12 -> r1.13)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/float8.sql.diff?r1=1.12&r2=1.13)
        oid.sql (r1.6 -> r1.7)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/oid.sql.diff?r1=1.6&r2=1.7)