Set font based on resolution if not set already

Change-Id: I6efaeb1c508c06513ac9ace7aa72a2eefa0cb1bb
Add command line capabilities

Allows sending openrecoveryscript commands to TWRP via shell.
This may be handy for visually impaired users, for various one
click utilities to drive TWRP commands from a computer, for using
TWRP when a catastrophic hardware failure like a shattered screen
prevents you from being able to use touch, or even on devices like
a TV stick where touch and USB mouse input is unavailable.

This patch also includes a few minor changes to openrecoveryscript
including proper support for rebooting via the script and for
decrypting the device via the command line.

Change-Id: I796ad168efdd2da9c25334ac93d1079daaa7b0bc