Release 2.0.0

[teubert]

Changes:

• Refactored GSAP to operate asynchronously, including automatic thread management to perform calculations on multiple threads.
• Added "simple" operational mode for resource constrained hardware.
• Replaced ProgData with discrete ProgEvent and SysTraj messages
• Created Load Estimator interface- for custom estimation of future loading
• Implemented savepts- specified moments in a prediction to report the predicted state
• Various bug fixes and efficiency improvements

[teubert]

@jason-watkins : I also updated the description to include release notes. Could you take a look at those as well?