convergenceControl: Store solve index per-field not per-entry

Resolves bug report https://bugs.openfoam.org/view.php?id=3173

 paraFoam: launches ParaView with Mesa OpenGL if exists

Can be overridden to use System GL by setting "export ParaView_GL=system" in .bashrc

streamlines: Updated tutorials for new caseDicts

foamGet: added directory target for scalar field s

thermophysicalModels: Added laminar thermal diffusivity for energy, a…

…lphahe

Needed for laminar transport of he (h or e)

Resolves bug-report https://bugs.openfoam.org/view.php?id=3025

Created tag for OpenFOAM-6

Updated git hooks to check new header format

Created tag for OpenFOAM-5.0

Created tag for OpenFOAM-4.0

Created tag for OpenFOAM-3.0.0