Summary of improvements

Show the value of the knob without clicking on it

Justification

When I want to know the value of a knob I have to click on it, but in some cases when I click, sometimes by accident I move the mouse and change the value of the knob.

I know that we have the option of '' reset '' to restore the default value, but it would be more practical if the knob will sho

Original discussion and maths breakdown:
FortySevenEffects/arduino_midi_library#203 (reply in thread)

Breakdown of the steps:

• Add a handlePitchBend callback
• Calculate a multiplicative factor (multiplied by the current note)
• Update the value passed to tone

Caveats / things to look out for:

• Note change while having bend on: the multiplicat

Right now dropping an address works, but the combobox only allows to select a device, not a port.

set a tree model with the devices & ports as combobox model maybe ?

Hydrogen version * : all
Operating system + version : all
Audio driver + version : all

A user suggested on linuxmao (the francophone linux-audio community) that it could be great to see the different patterns to scroll and to be showed when playing a song. Curren