Official TkDiff Version 5.5.2 Released

Owing to a user-identified set of crash conditions, there is yet a second "quick-fix" release being made. This time, the area affected involves startup situations that request any of the "inquiry-available" SCMs to nominate files that appear changed relative to a possibly stated revision point or range. As we equate a crash as being dead in the water, this rapid release is the result; our apologies to those who have just recently upgraded for the inconvenient thrash.