Improve support for comments in MS Word, including reporting the current comment with NVDA+alt+c and better announcement of the existance of comments within text.
Specifically:
* NVDAHelper winword support: collect the scope offsets for all comments in the current paragraph in one go, and then expose the comment attribute in the format field for a chunk if the chunk overlaps a particualr comment's scope. Also expose the comment's scope end offset (reference point) as the comment attribute's value. Previously comments were only being exposed on the last word of their scope.
* speech: announce when moving outside of a comment if extraDetail is true (moving by word or character).
* WinwordDocument NVDAObject: provide a reportCurrentComment script (NVDA+alt+c) that sees if the current character is in a comment and if so reports the text of the comment via speech and brzille.