What's new in 2.8.3.0:
MTP fixes and improvements - you can now copy zips to the root of storage - thanks to _that
MTP will now tell the host PC that storage is removed instead of disabling MTP completely
MTP will now report the correct max file size based on the file system in use to the host PC (may fix transfer of large files)
Update and improve fix permissions and make fixing contexts optional
Update SuperSU in TWRP to 2.40 and update install process
Make TWRP work properly on AArch64 (Nexus 9 is now built in true 64-bit binaries and libraries)
Attempt to set correct permissions and contexts on all files placed in storage so backups will show in Android
Fix kernel panic during MTP start on some devices
Support unicode fonts on devices with True Type Font support
Fix slider value not showing sometimes (vibration settings page)
Toggle MTP off during adb sideload to set correct USB IDs
Reduce library requirements for 5.0 L decrypt
Other minor fixes and improvements
