Wes 0.8.0

• Bugfix: 4 methods use wrong fill transform for the new animation system:
  • TweenTransforms.interpolate()
  • TrackEdit.insertKeyframe()
  • TrackEdit.replaceKeyframe()
  • TrackEdit.truncate()
• Added a new TransformTrackBuilder class.
• Added 2 more constructors for SkeletonMapping, to construct one-to-one mappings for an Armature or Skeleton.
• Targeted JME version 3.6.1-stable.
• Based on v8.7.0 of the Heart library.