Updated image preview a lot:
* Added a histogram-scope
* Added optional title-safe margins
* Re-arranged header, so that only usefull buttons are shown in image
preview mode
* Added zebra-mode for visual feedback of over-exposure regions
(helps in before and especially after color correction :)
* Added color-seperation-mode for waveform-display
* Show 10%, 70% and 90% hints in waveform-display
- blur works again (this was a serious bug in gamwarp...)
- seperates all sequence effects into a seperate file with a clean interface
- thereby fixing some obscure segfaults
- seperates the scope views into a seperate file
- adds float support to all effects and scope views
- removes a bad level call to open_plugin_seq
- FFMPEG seeking improved a lot.
- FFMPEG compiles with debian sarge version cleanly
- Makes hdaudio seek and resample code really work
