TODO
====
* optimize output plugin (uses most of the cpu).
* check out how much speed_eff may differ from 1.0 and still work properly.
* maybe a more elegant solution than calling gtk_adjustment_set_value()
   in pitch_change_cb() and scale_change_cb()
* check if pixmaps look good in other styles
* add query_format() and cleanup() functions for effect plugin
* remove clicks when changing speed/pitch
* autoconf/automake
* toggle big small overlap 1764 or 882 also for non-job-routines
* toggle volume correction also for non-job-routines 
* volume_correction maybe globally (not as argument - compatibility)
