support direct flashing (single or multiple images)

[steadfasterX]

SALT should allow flashing while in download mode.

Requirements:

• a secureboot off / unlocked device*

(*)The goal was always to allow flashing for locked devices, too. Flashing will work perfectly fine as long as your LAF protocol version is v100002 or lower but on later versions more work is required to workaround the new implemented protocol checks.

Enable flashing support with:

./salt --experimental

then choose Flash (folder)
note: Flash (kdz) is still WIP - do not use until finished! see #41