- fix insert_line to perform more as expected by adding a newline automatically
- add updated arm mkbootimg+unpackbootimg binaries from my AIK Build Farm, see my repos for changes
- rewrite backend to use proper exit codes from anykernel.sh now that it is shell
- fix ui_print and specific error messages by passing the outfd to anykernel.sh from the backend
- add error messages for unpacking and repacking ramdisk, and make resulting image size check into its own error message
- fix for cpio overwriting AK2 ramdisk files on some recoveries by using a tmp directory
- add further ramdisk unpack verification by checking that there are actually files in the ramdisk directory prior to moving the tmp files back
- add insert_file function to make multi-line additions easier
- add patch_fstab function to greatly simplify mount option/flag changes (thanks @Khaon for the idea)