Rebound

* WHFast512 now support the integration of 2 and 4 planet systems in parallel. Providing a speed up of up to 10x.
* The sqrt7 function used by IAS15 now support a wider range of input arguments.

* Removed distutils requirement in preparation for python 3.12.
* Removed rebound.InterruptiblePool as it no longer works with recent python version. Updated examples.
* Added Holmberg example.
* Added `adaptive_mode==3` for IAS15 (Aarseth 1985).

* Implemented own fmemopen implementation on MacOS. This is mainly to appease conda-forge builds.
* Improved sqrt7 algorithm allows larger convergence interval.

* Improved support for reading old and corrupted Simulationarchives.
* Renamed `ri_ias15.epsilon_global` to `ri_ias15.adaptive_mode`.
* Added new timestep method for IAS15 `ri_ias15.adaptive_mode = 2`. This is experimental for now. Details to be described in Pham, Rein & Spiegel (in prep).
* Added unit tests to check for fused multiply add instruction (these break reproducibility).
* Added phony target in C Makefile to force rebuilding librebound whenever building examples.

- Native Windows support. REBOUND can now be built natively on Windows (without WSL) using the Microsoft Visual Studio Compiler.
- Python Wheels are now provided for Linux, MacOS, and Windows. This should significantly speed up the installation process on a wide variety of systems.

* In python, Simulation and Particle objects are now picklable. Just like loading Simulations from a binary file, function pointers will need to be re-set manually after unpickling.
* The difference between simulations can now be printed out in a human readable form. Python syntax: `sim.diff(sim2)`. C syntax: `reb_simulation_diff(sim2, sim1, 1)`.
* Reading Simulationarchives with version < 2 is no longer supported.
* The POSIX function fmemopen() is now required to compile REBOUND. This should not affect many users. However, if you are using macOS, the version needs to be >= 10.13 (this version of macOS, High Sierra, was released in 2017).
* Internal changes on how Simulationarchives are written.
* Internal variable names that represent the size of allocated buffers now consistently include the name `N_allocated`.
* The TES (Terrestrial Exoplanet Integrator) has been removed. If you wish to use TES, you will need checkout an earlier version.