CintCPM - 32-bit Cintcode interpreter for CP/M-86

Currently only contains a Hello world for CP/M-86 compiled by GCC and
linked by RetroLinker.

Build instructions:

First, download all submodules:

$ git submodule update --init --recursive

Then, build RetroLinker, cpmtools, and libcpm:

$ cd RetroLinker
$ make
$ cd ..

$ cd cpmtools
$ ./configure
$ make
$ cd ..

$ cd libcpm
$ make
$ cd ..

Then, build Hello world:

$ cd hello
$ make
$ cd ..

Finally, run test VM with Hello world binary:

$ cd test
$ ./run.sh hello # Requires qemu-system-i386
A> B:HELLO
Hello world from GCC!