[waitbt] Add GPL, re-work WaitBt strategy

This "driver" currently might be useful to avoid STOP 0x7B errors
when booting from a volume connected via a bus which takes time
to initialize or find its child devices (think USB).

The printing and string manipulation is very hacky right now and
should be refined at some point.
# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#	new file:   gpl.txt
#	modified:   waitbt.c
#	modified:   waitbt.rc
#
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	waitbt32.sys
#	waitbt64.sys
