v0.5 - Reverb and playback status

Big update!

• Reverb has been added, making the FX channel useful. (#15)
• The FX and master channel meters now work.
• All meters now show level post-fader
• Faders are now controllable by scrolling (#30)
• Indicator lamps added to all tracks, showing green/yellow/red playback status (largely responding to #7)
• Transport moved to the right to make space for the player

Internals

• Track engine has been rewritten to make the player more robust (related to #26)
• The images are now published on tags and will include tag version (#24)