Use adb wait-for-recovery and adb wait-for-sideload

[tsterbak]

Maybe a lot of the sleep commands in the flashing steps can be removed by properly waiting. This also should increase stability of the process. Might not be supported on all devices or TWRP version?

To be tested.

[tsterbak]

Released in 0.4.1-beta

[EdoSecco]

Not sure if it is the right thread, but I've tried two times installing LineageOS on Samsung A5 2017, and after correctly install TWRP, and having the phone in recovery mode, I'm not able to go beyond this:

$adb -d reboot recovery
$adb -d wait-for-recovery