Synchronized the command line syntax to help with the "usage.md" documentation in both directions.
Added missing parameters, values, and explanations on both sides.
Extended the makefile, so changes to the includes (e.g. "syntax.inc") are automatically detected.
Added file extension detection based on host OS, so "mp.exe" can be built using the standard make in Cygwin for Windows.
This way, we can have a single makefile and don't need additional ".bat"s.
There are some unkown .bats on in the ".gitignore". I think we should remove them or add the ".bat"s in a proper scripts folder