Number tokens with a dollar sign are kind of cumbersome and don't really
serve a purpose, so I'm removing them.
Signed-off-by: Alek Ratzloff <alekratz@gmail.com>
It makes sense to allow users to set the initial register values. This
allows someone to e.g. enable interrupts once the VM has started, or set
the initial stack pointer value.
Signed-off-by: Alek Ratzloff <alekratz@gmail.com>