Update README.md

Minor fixes, forgot to mention that you have to install the JRE.  Oops.  Made source easier to read again.
Some GUI work
Just some properly layering to the XCF
Preparing to update Repo
Merge branch 'master' of https://github.com/pahimar/Equivalent-Exchange-3 into README
Update README.md

More apparent warning messages.
Made the Contributing section a bit better.
Minor stuff.
Merge pull request #204 from 50Wliu/README

Update README.md