[Android] Add stereo image widening option within the equalizer

[m8]

As per title, I'd love you to implement an option to widen the stereo image whilst playing local files and online streams alike - just like Poweramp's. Thanks a lot!

PS: and the ability to set "partial stereo", where 0% would be mono and 100% stereo, with all the in-betweens.

[Artem]

What this option should do?

[Soolo]

Как я понял, нужен такой ползунок: https://www.aimp.ru/forum/index.php?topic=45177.0

[m8]

Based on my привет-level understanding of Russian yes, that's what I mean for the PS! About the first request, I mean something down the lines of Poweramp's Stereo Expand knob.

[Artem]

Ok, now I understand. Usually it known as Stereo Enhancer.