Most legacy BIOSs will support USB legacy keyboard emulation. Using that
will avoid having to reserve memory for the USB drivers, and should
improve the chance of having a working keyboard without having to work
around various USB device quirks.
If the usbdebug option is present, pause at the end of the USB scan until
a key is pressed. Otherwise, if the keyboard=usb option is present and no
USB keyboards were discovered, pause for 10 seconds. Otherwise don't pause.
* Add preliminary support for TTY Serial/UART (#15)
* Use shadow_buffer instead of VGA buffer to get a framebuffer-agnostic TTY supprot
* Added menu browsing & inputs from Serial TTY (#15)
* Add fix for degree symbol on TTY. Correct serial.c & serial.h file created with CRLF (#15)
* Move tty_error_redraw() to insure correct redraw when a error occurs
* Many reindent / cleanup
* Various optimization from @martinwhitaker comments
