HTML attributes get double quotes
Hide image_url field and the uploader associated with it

This field doesn't get used any longer in report display.
Reorganize map layers link and image setting
Store the result of Tile.overlays

This makes a DB query, storing it in a variable reduces the number of
database roundtrips.
Moving `Tile` queries to the top of the JS file

Re-using the information inside the new `Story` JS object.
Removing an inaccessible function
Used in memory `tilesets` instead of `Tile.overlays` query
Wrap story.js in an immediately executed function

To reduce global namespace pollution
Change layout of image and map link in sections
Add a square preview style to `StoryAttachment` images
Raise `RoutingError` if there's no image found
Update the image preview when upload finishes
Update icomoon to add a plus icon
Display text that says uploading when an upload is in progress
Show a big '+' in the image preview space when there is no attachment
Return protocol relative urls from `attachment_url`
Put the editor toolbar color change in story.scss

The story_editor.scss file is not organized for editing
Slight re-organization of foldmarkers
Add translation strings for image removing and undoing
Make it possible to remove an image

And to undo removing the image.