Changed maximum volume to max PA_VOLUME_UI_MAX 150%

[optical-o]

Implements Issue #12 Uses PA_VOLUME_UI_MAX constant, which is recommended by the pavucontrol(150%.)

[pellea72]

Thank you. I was wanting the same thing. You saved me a lot of time figuring out where to make these changes. Whether or not this gets merged, you've made it easy for anyone to do this themselves.

[pellea72]

I'll just add that this could be command line option and/or set in a configuration file. I'm willing to look into doing that myself if there's interest.