20200616

• particles, contraints and forces can now be marked dead and are automatically disposed when calling Physics.step() or Physics.purge()
• added example for MuscleSpring
• added example for TearableSpring
• added example for VectorField
• added anatomy of a particle tutorial

20200528

• prepared library to be published on the processing.org website

20160423

• updated for processing3
• now using PVector for linear algebra
• removed dependency on mathematik

20150228

• initial release