npgsql - Npgsql2: [#1010488] NgsqlParameter of type containing DBNull

Log Message:
-----------

[#1010488] NgsqlParameter of type containing DBNull values throws NullReferenceException. Thanks Christ Akkermans for
testcase.Now, Npgsql handles first elements which aren't null as Arrays and IEnumerables. Also added test case for this
bug.

Modified Files:
--------------
    Npgsql2/testsuite/noninteractive/NUnit20:
        CommandTests.cs (r1.18 -> r1.19)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/testsuite/noninteractive/NUnit20/CommandTests.cs.diff?r1=1.18&r2=1.19)
    Npgsql2/src/NpgsqlTypes:
        ArrayHandling.cs (r1.4 -> r1.5)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/src/NpgsqlTypes/ArrayHandling.cs.diff?r1=1.4&r2=1.5)