Tweaked the README to be a bit more friendly and detailed

I thought the README could use some love, so I added some details about licensing and also detailed out procedures for downloading and building the project.

In addition I added a bit to the "What do you get" paragraph and tried to tighten it all up some.
Again, I don't think we need this kind of hand-holding to tell developers how to run build.cmd. If something goes wrong, I doubt it will be navigating to the correct directory or not knowing how to run a cmd file.