initial commit of new LwjglHeadlessApplication for a headless libgdx,
some LwjglApplication cleanup
add Apache Header
fix natives for LwjglHeadlessApplication
new Application type HeadlessDesktop for LwjglHeadlessApplication
Merge remote-tracking branch 'upstream/master' into headless
modify CHANGES
Merge pull request #1018 from jrenner/headless

initial commit of new LwjglHeadlessApplication for a headless libgdx