Fix bogus options passed to generated items compilation

[pepone]

This PR fix to interrelated bugs with the builder:

• Items that are automatically added by the SliceCompile task, because they are not part of the project, inherit the SliceCompile options instead of the options specified for the generated item ClCompile in C++ projects or Compile in C# projects
• Because the automatic items include attribute directly used the OutputDir property, the excludes attribute only matched files in certain circumstances.