npgsql - Npgsql2: Added patch from Patrick Earl.

Log Message:
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Added patch from Patrick Earl. Thanks, Patrick! http://pgfoundry.org/forum/message.php?msg_id=1014749

This was implemented to support more of the NHibernate test suite. Here is what it does and does not do:

1. It adds support for the "ForeignKeys" collection that uses almost the same format that SqlConnection Server does.
Theonly difference is the deferrable bool columns are actually bools instead of strings. 

2. It fixes the restrictions for index and index column schema retrieval.

3. It does not change the index column code to provide the capability of getting the foreign key columns (assuming it
doesn'tdo it already). I didn't have a failing test depending on this, so I didn't check or implement anything here. 

http://patearl.net/files/Npgsql2.patch

Modified Files:
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    Npgsql2/src/Npgsql:
        NpgsqlConnection.cs (r1.33 -> r1.34)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/src/Npgsql/NpgsqlConnection.cs?r1=1.33&r2=1.34)
        NpgsqlSchema.cs (r1.7 -> r1.8)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/src/Npgsql/NpgsqlSchema.cs?r1=1.7&r2=1.8)