Allowing for Key and Column attributes, and continue on key.

[rwood]

CacheDictionaryProperties wasn't being used.... should it?

There was an error if the Key attribute and Column attribute were both on a property. Since Key inherits from Column var colAttr = property.GetCustomAttribute(typeof(ColumnAttribute)) as ColumnAttribute; threw an exception.

Another error, when the Key attribute was present the column and value were added to the Where clause, but then also added to the Set clause. This throws an exception from the db (at least on SQL Server). Adding a continue; to skip the Set clause for the Key.