Underworld

---------------------------
New:
* New Dockerfile configuration resulting in smaller docker images.
* Move to Petsc-3.18.1.

Changes:
* Multiple mpi implementation images for HPC usage (Gadi and Setonix).

Fixes:
* Revert to HDF5 1.10. Fix for Checkpointing issues.

---------------------------
Fixes:
* Improved CMAKE workflow.
* Fixes to failing unit tests.
* Dockerfile updates - revert MPICH version to 3.4.3.

-----------------------------

New:
* Merge UWGeodynamics into Underworld (`from underworld import UWGeodynamics as GEO`)
* Compatibility with petsc 3.17.
* Update Docker images: Ubuntu 22.04LTS and mpich 4.0.2, python 3.10, petsc 3.17.1
* Update install_docs/nci gadi

---------------------------
New:
* CMake based builder instead of Scons.
* Added M1 (arm64) based docker.
Upcoming release
Changes:
* GitHub actions for CI and docker publications.
* Compatibility with petsc 3.16.
* Update Docker images: Ubuntu 21.10 and mpich 3.4.2, python 3.9.2, petsc 3.16
* Update install_docs/nci gadi

Fixes:
* Unit fix for temperature saved in celcius.

-----------------
Changes:
* Enabled user defined Gauss integration swarms for all systems.
* Update docker base images: switch to ubuntu(20.04), update petsc(3.14) & mpich(3.3.2), other tweaks.
* Cleaner Python compile time configuration.
* Add runtime check for solver availability (for example, 'mumps'). Also add test for check.

Docker image changes:
* Update base image.
* Updated to PETSc 3.15.1
* Updated to MPICH 3.4.2
* Removed petsc4py.
* Switched `/opt` to ugo+rwx to allow users to install Python packages.

New:
* Model for EBA convection, based on King et al. (2010) benchmarks. See `docs/test/14_Convection_EBA.ipynb`
* Mesh/MeshVariable/Swarm/SwarmVariable objects now support loading and saving
of units information, as well as additional attributes. For usage examples,
see `docs/test/mesh_aux.py` and `docs/test/swarm_aux.py`.
* Added `underworld.function.count()` method, which counts function calls.
* Conda binaries available via underworldcode conda channel `conda install -c underworldcode underworld2`
* Added `underworld.function.count()` method, which counts function calls.
* Added GADI install/run scripts ./docs/install_guides/nci_gadi/
* Updated pull request related documentation and added template.

Fixes:
* Updates for SCons4.1.
* Fix bug where multiple solvers added multiple preconditioners.
* H5py v3 is more strict in allowed indexing array shapes. Updated our
structures to accomodate.
* Tester uses `jupyter-nbconvert` which no longer defaults to Python. Update
to explicitly select Python.
* Switched h5 file save to mode "w" instead of "a" as append mode resulted
in data from previous datasets (with identical name) not being removed from
file, and file sizes therefore growing unnecessarily.

---------------------------
Changes:
* Updating Dockerfile to include UWGeodynamics new docs structure.