Time-stretching

[sialivi]

I listen to a lot of podcasts, but the lack of adjustable playing speed (time-stretching) is forcing me to use other software for podcasts.

I know there are 3rd party plugins, but they don't integrate very well with MM, and this functionality really needs to be built in.

My feature request is twofold:
1) Implement time-stretching (maybe via this library, http://breakfastquay.com/rubberband/index.html )
2) Remember the playback speed on a per podcast basis, since some needs to be sped up more than others.