AMIGAOS: Get rid of the OS version number

"4" is the version of the OS. It will certainly change with future updates.
AMIGAOS: Cleanup of the AmigaOS version number
AMIGAOS: Add a stack cookie

Setting up a static stack to avoid crashes from a stack set too low.
Merge pull request #489 from raziel-/patch-1

AMIGAOS: Stack cookie and no more AmigaOS version number