npgsql - Npgsql2: quote identifiers when generating sql

Log Message:
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quote identifiers when generating sql

Modified Files:
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Npgsql2/src/Npgsql/SqlGenerators:
SqlSelectGenerator.cs (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/src/Npgsql/SqlGenerators/SqlSelectGenerator.cs.diff?r1=1.5&r2=1.6)
VisitedExpression.cs (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/src/Npgsql/SqlGenerators/VisitedExpression.cs.diff?r1=1.5&r2=1.6)
SqlBaseGenerator.cs (r1.10 -> r1.11)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/src/Npgsql/SqlGenerators/SqlBaseGenerator.cs.diff?r1=1.10&r2=1.11)