v1.2007031541

This version brings a major update to Kanmail including an
overhaul of the column and thread designs and a number of
fixes.

Changes:

• Fix Quill editor to use div instead of p for blocks.
• Fix call to delete header items.
• Ignore null thread references.
• Remove pointless keyboard disabling.
• Major overhaul of main emails app design.
• Add randomcolor npm package.
• Default yes to all release script prompts.
• Don't apply dragging functions when not frameless.
• Add get contact icons + group single threads settings.
• Enable cross origin access in dev for usable stack traces.
• Fix incorrect decoding of attachments (leave as bytes).
• Accept the session token as a URL parameter as well as header.
• Add API to fetch icons for emails.
• Rename send app less file.
• Show JS error tracebacks.
• Enable merging threads by subject behind a flag.
• Add logic to enable merging single emails from the same sender.
• Don't include column meta count if the folder does not exist on the server.
• Stop closing thread on keyboard shortcuts.
• Add makeNoDragElement function.
• Move makeDragElement into window.js.