* improve space reserving, allows write better 4K/8K video data
* do not use cache dirs in the muxers, Android can force close NewPipe if the device is running out of storage. Is a aggressive cache cleaning >:/
* (for devs) webm & mkv are the same thing
* calculate the final file size inside of the mission, instead getting from the UI
* simplify ps algorithms constructors
* [missing old commit message] simplify the loading of pending downloads
* re-work finished mission database
* re-work DownloadMission and bump it Serializable version
* keep the classic Java IO API
* SAF Tree API support on Android Lollipop or higher
* add wrapper for SAF stream opening
* implement Closeable in SharpStream to replace the dispose() method
* do required changes for this API:
** remove any file creation logic from DownloadInitializer
** make PostProcessing Serializable and reduce the number of iterations
** update all strings.xml files
** storage helpers: StoredDirectoryHelper & StoredFileHelper
** best effort to handle any kind of SAF errors/exceptions
* 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
kapodamy