Implementing the heat equation eoc test.

examples/heat-equation/tnl-run-heat-equation-eoc-test

src/config/tnlConfigDelimiter.h

src/config/tnlConfigDescription.h

src/config/tnlConfigEntry.h

src/config/tnlConfigEntryBase.h

src/config/tnlConfigEntryList.h

src/config/tnlParameterContainer.cpp

src/config/tnlParameterContainer.h

src/core/tnlDataElement.h

src/core/tnlString.h

src/functions/tnlFunctionDiscretizer.h

src/functions/tnlTestFunction.h

src/implementation/core/tnlString.cpp

src/implementation/functions/tnlFunctionDiscretizer_impl.h

src/implementation/functions/tnlTestFunction_impl.h

...mentation/operators/tnlDirichletBoundaryConditions_impl.h

src/operators/tnlDirichletBoundaryConditions.h

tests/benchmarks/tnl-benchmark-linear-solvers.h

tools/src/tnl-init.cpp

tools/src/tnl-init.h