NH-3586

Fixed Decimals with precisions larger than 18
Merge commit '251ed3b4433f17b24d3e7cf29550d1ba3a386be4' into NH-3586
FirebirdDialect, FirebirdDialectFixture: Fix indents.
Criteria/CriteriaQueryTest.cs: Add some missing using statements.
Merge branch 'NH-3586'