CardReader: Change standby message.

Display control error messages on Cardreader display
Reset Cardreader display after 4 seconds of idle to make sure the display is clean
when a new user inserts a card.
Detect a dead portal control and display an error message.

reader power completely).
CardReader: Send reply when an LCD command is complete.

Cardreader: Switch card power in software
Cardreader: Cleanup some dead code
Cardreader: Change IO Pins and Clockgen Timer to match new hardware.
Cardreader: Update LCD lib and set 4 bit mode pins.
Cardreader: Fix racecondition where serial interfaces bytes can get lost while processing an LCD command. The sender will now be notified when the commadn is complete.
Control: Support low battery shutdown override in new UPS.
Control: Support diabling keyslots
Control: Re-enable IDLE sleep mode.
Control: Change Cardreader power request pin polarity (high = power needed)
Control: Support RNG power software control (currently always on, to be changed).
Control: Update shell help command, to list all commands.

Rework of card reader protocol and code. It now uses a generic transport protocol with error checking (CRC16).
Rework card reader interface, it now drives the LCD and card remotely.
Switch key storage to external EEPROM.
Cache only the first 4 byte of key hashes in RAM, not the full hash.
Replace old single char commands with a management CLI. Currently a hardcoded login is used. This is subject to change.
Use an external hardware RNG for random numbers. Thanks to StuC for building this nice piece of Hardware.
Disable power save modes for now.
Enable Brown out detection to avoid accidental door commands on power fail
Update schematics.

CardReader: Add timeout to LCD busy waits.
CardReader: Discard host receive buffer after waking up.
CardReader: Enable card clock only when needed.