- remove "Change" label and replace with larger dash preview icon.
The "change" text is unnecessary and adds to dialog clutter, better
to use the space for a wider preview icon (especially given that
the previous narrow icon never really showed enough of the pattern
to be useful!)
- don't offset the line in the preview if the symbol has an offset
set
- respond correctly to dash pattern, line width unit changes, cap
style changes
- show a nice big preview tooltip on hover
8d180c1e8a