1.1.0

• added new scenes
• added implicit viscosity (Bender and Koschier, "Divergence-free SPH for incompressible and viscous fluids", IEEE Transactions on Visualization and Computer Graphics, 2017)
• added Projective Fluids implementation (Weiler et al., "Projective Fluids", Proceedings of Motion in Games, ACM, 2016)
• updated CompactNSearch
• updated PositionBasedDynamics
• optimized DFSPH
• updated to Eigen 3.3