Only specified part is not muted

<part>o - mute everything except part
o - unmute everything
<part>m - mute only the specified part
m - mute everything
Mute All UnMute All in part view

shift+m for mute all
shift+o for unmute all
Fix g keystroke
Merge pull request #19 from chriserin/only-part-is-not-muted

Only part is not muted