Playback Speed improvements

[xeo]

1. In Playback Speed menu under Playback Speed slider you could add a checkbox option for remembering of the setting, like "Remember this setting" that would work such that when it's enabled the pitch and playback speed is always remembered for all files. When it's disabled it's set/remembered only until next file is open.
2. You could also add a button at place where the value is shown (above the sliders) for quickly choosing main values like 0.75, 1.0, 1.25, 1.50.
3. Pitch settings and playback speed could also be executed/working right away after changing the setting even before accepting with OK.
4. Area of tapping the playback speed value is too little (hard to open playback speed/pitch settings).
5. Space/margin above "Pitch" (playback speed/pitch settings) is too big.