* allow retry downloads with "post-processing failed" error in the new muxer
* MPEG-4 muxer ¡¡ no DASH output!!
* keep the progress if download fails
* remove TODO in SecondaryStreamHelper.java
* misc clean-up
* delete TestAlgo.java
* delete ExtSDDownloadFailedActivity.java and remove it from AndroidManifest.xml
* use hardcored version for changing icon colors