[Accessibility-ia2] Suggestion: change all grouPosition items to 1-based index

[Aaron Leventhal]

Currently groupPosition is out-of-sync with the 
ARIA spec. The ARIA spec makes all of these items 
1-based.

Two of them are 0-based. I suggest changing to 
make the same as ARIA, in order to avoid "off by 
1" errors because of API differences.

/** @brief Returns grouping information.

   Used for tree items, list items, tab panel 
labels, radio buttons, etc.
   Also used for collectons of non-text objects.

   @param [out] groupLevel
    0-based
   @param [out] similarItemsInGroup
    1-based
   @param [out] positionInGroup
    0-based
  */
  [propget] HRESULT groupPosition
    (
     [out] long *groupLevel,
     [out] long *similarItemsInGroup,
     [out, retval] long *positionInGroup
    );