set next release version to 4.4.1 (opensim-org#3513)

Release 4.4 codebase

Introduce OPENSIM_PYTHON_CONDA (opensim-org#2989)

* Introduce OPENSIM_PYTHON_CONDA to disable copying/duplicating runtime libs on windows

* Use more modern find_package Python3 so that Numpy is found along with python

* Require CMake 3.15 to enable use of Python3 and Numpy using CMake facilities directly

* Reduce required python version to 3.6 and remove need for development component

* Update continuous_integration.yml

try to force numpy install using python3

* Update continuous_integration.yml

Use pip instead of pip3

* Add back Development to locate include paths

* Remove add_dll_directory in __init__.py

* Use Python3 specific CMake variables throughout

* Update continuous_integration.yml

Use more recent version of setup-python on windows to try force using python 3.8 throughout

* Update continuous_integration.yml

Try passing Python3_ROOT_DIR on command line to CMake

* Update continuous_integration.yml

Fix formatting

* Remove stale line

* modify comment in __init__.py

* Restore __init__.py and separate python bindings tests

* Change location of python package dependeing on CONDA layout

version 4.3

Official 4.2

This release uses an updated version of opensim-core that includes

SmoothSphereHalfSpaceForce, which has now been removed from the Moco
codebase. The interface to this class has been updated to use
OpenSim's ContactSphere and ContactHalfSpace classes, so your models
must be updated in order to continue using this component. You can refer
to the gait model included with example2DWalking for the correct XML
syntax and view a file "diff" of the changes here:
opensim-org/opensim-moco@ccd39f8#diff-eb627df1f2a265a84a30b7c6b4f92999.

Contact tracking was added as an option to example2Dwalking, and
MocoContactTrackingGoal was updated to support contact spheres
distributed across multiple bodies. MocoControlTrackingGoal was updated
to more easily associate controls to reference data, as demonstrated by
a new electromyography tracking option added to exampleMocoInverse.  A
"projection" setting was added to MocoFrameDistanceConstraint to
provide more flexibility in posing this constraint.

DeGrooteFregly2016Muscle's passive force multiplier now has a stiffness
parameter. To support this change, the curve was tweaked slightly. This
may have a minor effect on solutions relying on passive fiber forces.
The maximum difference between the new and old passive force-length
curves is 0.07 (unitless).

Finally, we've included various bug fixes in this release:
- Fixed a bug where MocoPeriodicityGoal incorrectly specified control constraints
- Fixed an error that occurs when using ModOpRemoveMuscles
- Fixed some default pelvis and lumbar parameters in createPeriodicTrajectory()
- Added some missing MATLAB and Python commands to the bindings

More details about this release are in the CHANGELOG.md file.

Change "Labels" to "labels" to reduce confusion. (opensim-org#2669)

OpenSim Moco 0.3.0

Two major additions are included in this Moco release: reporting
the breakdown of solution objective terms and contact force tracking.

When using MocoCasADiSolver, MocoSolution now provides a breakdown of
the terms in the objective. The portions of the total objective for all
terms (including their weights) can be accessed by the methods
getObjectiveTerm() and getObjectiveTermByIndex() on MocoSolution, and
are also printed to the command line or console window upon arriving at
a solution.

MocoContactTrackingGoal was added, allowing minimization of error
between model compliant contact forces and experimentally measured
contact force data. Currently, this goal does not track torques or
centers of pressure, and only supports the SmoothSphereHalfSpaceForce
contact element included with Moco.

Other minor changes in this release include renaming exampleSitToStand
to exampleSquatToStand, moving the bisection root solver in
DeGrooteFregly2016Muscle to a dedicated utility in MocoUtilities, and
a bug fix in the report.py report generation tool related to the
STOFileAdapter no longer have a read() method due to a recent change
in OpenSim's API.

These changes, and changes from previous releases, are reflected in
CHANGELOG.md.

OpenSim Moco 0.2.0

This release contains a MATLAB version of Moco's 2D predictive
simulation of walking, contributed by Brian Umberger, and examples in
MATLAB, Python, and C++ for using the MocoInverse tool. Lastly, we added
examples for creating a custom goal in C++; see
exampleSlidingMassAdvanced.cpp and exampleMocoCustomEffortGoal.

To easily plot a solution in MATLAB, we introduced the
osimMocoTrajectoryReport.m utility.

We updated the versions of Simbody and OpenSim that we bundle with Moco.
As a result, this release contains a fix for the simbody-visualizer for
macOS Catalina, and contains OpenSim's support for IMUs.

This release contains the following new modules:
- MocoOutputGoal, for minimizing any scalar output of a model.
- MocoFrameDistanceConstraint, to constrain the distances between frames
in the model.
- MocoAngularVelocityTrackingGoal and MocoAccelerationTrackingGoal,
added in anticipation of supporting IMU data in the future.

We made minor changes to various parts of Moco's interface; you may have
to make small changes to your code to use this release. For example,
converting muscles from Millard2012EquilibriumMuscle to
DeGrooteFregly2016Muscle now preserves the fiber damping property, while
previously we set fiber damping to 0 during this conversion. To set
fiber damping to zero, you can use ModOpFiberDampingDGF.

More details about this release are in the CHANGELOG.md file.

This version was used to generate the results for the Moco preprint.