npgsql - Npgsql2: Remove dependencies upon System.Drawing.

Log Message:
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Remove dependencies upon System.Drawing.

Make NpgsqlInterval clonable

Modified Files:
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Npgsql2/src/NpgsqlTypes:
NpgsqlTypes.cs (r1.4 -> r1.5)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/src/NpgsqlTypes/NpgsqlTypes.cs.diff?r1=1.4&r2=1.5)