script to download and build deps. updated README. add gitignore. remove build products from repo.

[EsGeh]

This hopefully makes this repository a lot easier to use.
I expect the maintenance overhead to decrease too.

dependencies are being managed by the experimental fish script https://github.com/EsGeh/git_deps.
All dependencies are exactly specified in the file ./dependencies.fish.

It's just a suggestion. Let's discuss :-)

[TheKikGen]

Why not writing a how to with the existing components first ?

[EsGeh]

Hmm. My script and modifications are pretty much based on github issue 6 and the wiki of this repository.
After having figured out how to compile and use USBMidiKliK I just thought I could share this solution in the form of a reproducable script to simplify things.
In my opinion a script can be considered executable documentation.
But it's a question of taste, I guess.
Basically, it solves the following problems:

• document dependencies including the exact versions (via git hash)
• automatize and document the process of downloading and building the dependencies
• avoid confusion about how to create the correct directory hierarchy
• simplify integration into other projects and scripts

I added the necessary documentation to the README file.

All one has to do is to enter

$ ./scripts/init.fish
$ make

I am already using https://github.com/EsGeh/git_deps in some other projects and it works pretty well, so far.
There are still things that can be improved (e.g. providing better output and logging).
Integrating these improvements will be as simple as changing a git hash in ./scripts/init.fish.