Before this commit, the graphics window edit control always had
a width of 30 average character widths.
After this commit, the edit control has a width of 5 average
character widths (for numeric constraints) or 30 average character
widths (for comment constraints), or just enough to display
the entire value being edited, whichever is greater.
This makes the edit control overlap the sketch less in case of
editing numeric constraints (since in most cases, the numbers being
edited are short), and removes annoying scrolling in case of editing
long comments.
23dc36da9b