Trim SetCustomFieldData and GetCustomFieldData
Trim SetCustomFieldData and GetCustomFieldData

Some types of custom fields are never created by FDO, so there's no
point in having code around to handle them. We can bring this code back
later on if FDO ever allows those field types.

ermshiperete/LfMerge,ermshiperete/LfMerge,sillsdev/LfMerge,sillsdev/LfMerge,sillsdev/LfMerge,ermshiperete/LfMerge