Suggestion: mixer selection same as channel rack selection?

[pakunoda]

I think it would be nice to have the same selection mode in the channel rack and the mixer in FL12.

In the channel rack, using only the left mouse button, we can:
- click and reclick the same channel selector to select all the channels
- click and hold channel selectors to select multiple contiguous channels.

In the mixer, to select multiple tracks, the CTRL key is needed.
An alternative could be click-and-hold the track numbers (though I suppose these are just labels and not button).
And click and reclick the same track could select a group (would select all the tracks if there is no group yet).