use maven repo version of j-ogg and j-vorbisd
clean up some naming in SDK build.gradle
- update JmeVersion automatically in build script
- change handling of version "tag" (stable, svn etc.)
Bugfix: fix that allows to use either quaternion or euler rotation in
bone animation.
Make gradle generated pomfiles uploadable in nexus

Use the gradle-nexus-plugin to let generated artifacts
be uploaded to nexus with uploadArtifacts tasks.

Requires nexus username and password in ~/.gradle/gradle.properties
See https://github.com/bmuschko/gradle-nexus-plugin

Also add more build stuff in gitignore