**video demo:** https://www.youtube.com/watch?v=tbghtqziB1g
This branch adds a new extension, Auto-Route Satin Columns, implementing #214! This is a huge new feature that opens the door wide for exciting stuff like lettering (#142).
To use it, select some satin columns and run the extension. After a few seconds, it will replace your satins with a new set with a logical stitching order. Under-pathing and jump-stitches will be added as necessary, and satins will be broken to facilitate jumps. The resulting satins will retain all of the parameters you had set on the original satins, including underlay, zig-zag spacing, etc.
By default, it will choose the left-most extreme as the starting point and the right-most extreme as the ending point (even if these occur partway through a satin such as the left edge of a letter "o"). You can override this by attaching the new "Auto-route satin stitch starting/ending position" commands.
There's also an option to add trims instead of jump stitches. Any jump stitch over 1mm is trimmed. I might make this configurable in the future but in my tests it seems to do a good job. Trim commands are added to the SVG, so it's easy enough to modify/delete as you see fit.
This branch adds a new command to split a satin column at a specified point. The split happens at a stitch boundary to ensure that the two resulting satins sew just like the original. All parameters set on the original satin remain set on the two new satins, and all rungs are retained. If one of the satins would have no rungs left, a new rung is added.
How to use:
1. Select a satin column (simple satin doesn't work)
2. Attach the "Satin split point" command using the "Attach commands to selected objects" extension.
3. Move the symbol (or just the connector line's endpoint) to point to the exact spot you want the satin to be split at.
4. Select the satin column again.
5. Run "Split Satin Column".
6. The split point command and connector line disappear, and nothing else appears to have happened. Select your satin and you'll see that it's been split.
This extension is a by-product of my initial work on #214. Ink/Stitch will need the ability to split a satin at an arbitrary point, and I figured, why not go ahead and release that functionality as an extension while I'm at it? :)
You can't have a module and a package named the same thing. PyInstaller wants
to import the main script as if it were a module, and this doesn't work unless
there's no directory of the same name with a __init__.py in it.