[Issue Type] Custom member formulas and custom rollup formulas are migrated into MDX script [Issue Description] 
In previous versions of Analysis Services, the following properties are supported on dimensions and levels: custom rollup formulas, custom member formulas, All member formulas, and custom level formulas. In SQL Server 2005 Analysis Services, these properties were replaced by functionality supported in Multidimensional Expressions (MDX) scripts, and are upgraded to MDX scripts during migration.