1.0.55

• Removed the redundant getBoundingCenter() methods from the PhysicsSoftBody class.
• Renamed the setMacDisplacement() method in the SoftBodyWorldInfo class.
• Upgraded the Bullet sources to match SHA1 ID=f4f5f708 of the bullet3 project.
• Added 9 methods to PhysicsSoftBody:
  • addVelocity()
  • getAnchorCount()
  • getClustersPositions()
  • getNodeLocation()
  • getNodeNormal()
  • getNodesNormals()
  • getNodesVelocities()
  • getNodeVelocity()
  • setVelocity()