Format output a little nicer
Permissions
Change to correct checksum

The only documentation I could find online on how the checksum is
calculated said it's the one's compliment of the sum of all bytes
transmitted in the message so far. After capturing the transactions from
existing ALDL software, it seems that it should actually by the two's
compliment.

This still needs to be tested though... again, a job for tomorrow, when
it is light out.
Add captured ALDL transactions

The ALDL data stream was captured from existing ALDL software in Windows
while the ignition was switched to "on" but without actually starting
the engine. The captured data is in the zip file added with this commit.
Transmit "return to normal mode" before exiting