BUG: fixed a bug in NewtonSolver that limits num of iterations to 1; added test case for NewtonSolver; renamed file imstkNonlinearSystem to be consistent;

REFAC: upgrade to vega-4.0

See merge request iMSTK/iMSTK!452

COMP: Fix compilation errors on gcc

See merge request iMSTK/iMSTK!451

REFAC: Use forward declerations where possible

See merge request iMSTK/iMSTK!448

# Conflicts:
#	Source/Common/Utils/imstkTimer.h
#	Source/Common/imstkModule.h
#	Source/DynamicalModels/ObjectModels/PbdConstraints/imstkPbdFETetConstraint.cpp
#	Source/Scene/SceneElements/Objects/imstkVisualModel.cpp
#	Source/Scene/SceneElements/Objects/imstkVisualModel.h
#	Source/SimulationManager/imstkViewer.h

BUG: Clear compilation errors on Ubuntu

See merge request iMSTK/iMSTK!447

Move make_unique definition to the common library

Fix imstkFind.cmake

See merge request iMSTK/iMSTK!443

REFAC: Remove make_shared from decleration to initializer list

See merge request iMSTK/iMSTK!446

Ensure that a library is not created multiple times. Otherwise you may get
the following error:
CMake Error at .../iMSTK-build/install/lib/cmake/iMSTK-2.0/modules/imstkFind.cmake:192 (add_library):
  add_library cannot create imported target "g3log" because another target
  with the same name already exists.

or:

CMake Error at .../iMSTK-build/install/lib/cmake/iMSTK-2.0/modules/Findg3log.cmake:17 (target_link_libraries):
  Cannot specify link libraries for target "g3log" which is not built by this
  project.

Unity integration

See merge request iMSTK/iMSTK!442

ENH: Enable CUDA in CMake configuration

See merge request iMSTK/iMSTK!432

Unity integration

See merge request iMSTK/iMSTK!440

REFAC: Remove references to solver in the pbd examples

See merge request iMSTK/iMSTK!441

Update iMSTKConfig.cmake

See merge request iMSTK/iMSTK!431

Refactor logger

See merge request iMSTK/iMSTK!439

Add options to disable sinks in simulation manager
Make logger singleton