Documented the main makefile better

Explained some of the details that were missing explanations.

Signed-off-by: Joel Nider <joel@nider.org>
JOEL4: outlined L4_DebugPutChar

I am trying a new method of passing the parameters for system calls by
leaving them in the caller's stack frame and only passing the address.
The inline version doesn't work anymore because there is no stack frame.

Signed-off-by: Joel Nider <joel@nider.org>
Merge pull request #33 from jnider/dev

Dev