Add multitrack player with solo, mute, volume

[rualark]

• [x] Play, pause, stop
• [x] Click, dblclick, rightclick
• [x] Slider
• [x] Solo and mute
• [x] Apply volume
• [x] Auto volume
• [ ] Before saving volume, check that instruments did not change
• [x] Report chrome crash

[rualark]

Currently MT5 takes 500Mb RAM for 41Mb of MP3 files (12 files 3:20 each) - 128Kbit (Daisy Daisy) - loading takes 40 seconds 12 Jplayers take 140 Mb

[rualark]

Jplayer solution (multitrack2.php) is unstable and sometimes does not synchronize good

[rualark]

Multiple web audio for MWC (4:08 x 38 tracks each 7.6Mb) loads during 3:10 and takes 700 Mb RAM

[rualark]

• Play, pause, stop
• Click, dblclick, rightclick
• Slider
• Solo and mute
• Apply volume
• Auto volume