Netduino_TIM2_5: General updates based on datasheet

Now it actually works :)

Signed-off-by: Alistair Francis <alistair23@gmail.com>
Netduino: HACKish This no longer requires the reset change

Needs tidying, renaming and some reordering

Signed-off-by: Alistair Francis <alistair23@gmail.com>