Dev Version 1.4.0-dev.0

• added comments to all py files for better troubleshooting and readability
• added the fade engine from the roaming music integration to;
  • add better error handling
  • add global sync group member resolution
  • add handling of unavailable speakers gracefully
• updated manifest to v1.4.0-dev.0

What's Changed

• dev code comments by @connochio in #63
• dev fade engine by @connochio in #64

Full Changelog: v1.3.1-r.0...v1.4.0-dev.0