Add a note to the README about supported SBT versions.
The lwjgl-platform natives in Maven are called osx, not macosx
Merge pull request #33 from abesto/sbt-version-notice

Add a note to the README about supported SBT versions
Merge pull request #34 from abesto/osx-natives-name

The lwjgl-platform natives in Maven are called osx, not macosx