Merge upstream commits up to 0.9.7

[Low-power]

Hello.

I originally plan to file this as a pull request, but since I rebased the entire history of all your commits, then connected them into upstream repository, GitHub didn't let me create a pull request for no common history between the 2 branches.

The branch I intended to suggest you to merge is available at https://github.com/Low-power/DOSMid/tree/cms. If you want, you can import this branch into your repository; may be using following commands for example:

git remote add Low-power https://github.com/Low-power/DOSMid.git
git fetch Low-power cms
git checkout -b cms Low-power/cms
git push cms

Original pull request body

This is my attempt to integrate your commits with the upstream source repository (https://svn.code.sf.net/p/dosmid/code/), and update to latest upstream version (0.9.7). In addition to the complete version history, it will also make merging upstream updates much easier, when any new upstream version came out in future.
I have converted the upstream source repository from Subversion to Git, then imported and rebased your Git repository into an unified repository.

Due the some incompatibilities with your repository and the upstream repository, I have to rebase the entire repository with some changes; as a result, this branch can't really be merged into your existing branch.

Changes to existing commits include:

• Correct all-uppercase file names. Your source tree uses all-uppercased name for all files, this is different from the upstream source tree.
• Convert source files from Unix line ending (LF) back to DOS line ending (CRLF). All of your source files have Unix line ending, which is different from original source files.
  The above 2 issues have to be resolved to enable this fork to continue keep sync with upstream updates in future.

In addition, I also made some minor fixes and improvements to the source tree:

• Remove the build output dosmid.exe. Please don't store the build output files in source repository, use Releases for that instead.
• cms.c uses function outp, which requires an inclusion of conio.h.
• Remove unused variable definitions, because new upstream Makefile configures the compiler to fail on warnings.
• Add a makefile for GNU Make; this enables the program be cross-built from GNU/Linux.