A way to create playlists from selection inside folder [FEATURE]

[sonofevil]

Is your feature request related to a problem? Please describe.
As the documentation states, shortcuts and drag and drop on folders gets applied to every child item. Drag and drop can be used in foo_plorg to quickly create playlists inside folders. This doesn't seem to be currently possible in PM-SMP.

Describe the solution you'd like
A way to configure drag and drop to create a new playlist in a folder or a context menu item for folders to create a new playlist from selection.

Describe alternatives you've considered
Of course one could create playlists outside the folder and then drag them into the folder, but that is a somewhat tedious extra step.

[regorxxx]

I see, essentially this (from the + button) at folders:

I think it should also be possible to tweak the alt+drag n drop behavior to create the new playlist inside the folder under the mouse, instead of putting it at the root.

[regorxxx]

Implemented.
Drag n drop later.

[regorxxx]

Drag n drop should work now.