Node searching methods need to know whether they process only base nodes or all nodes including nonlinear
calculate node distance in element and mesh
support node distance in HeuristicSearchLength
First implementation of catalyst/vtk integration.
Dummy VTU reader for testing.
Install CMake 3.0.2 on Travis.

This is using the prebuilt version from cmake.org which is 32 bit.
Therefore some 32-bit compatibility packages have to be installed
as well (but they should be cached by Travis on future builds).
Add CMake's bin directory to the path.
Speedup catalyst build by just building vtkIO for now.
Moved VtkMeshConverter to MeshLib/MeshGenerators.

Builds now both in CLI as well as GUI configuration.
Setting up files and directories for in-situ classes.

Started implementing mesh node coordinates wrapper.

Conflicts:
	CMakeLists.txt
Implementation of read only methods and a simple test.

There is lots of boilerplate code which is required, see also
https://github.com/Kitware/VTK/blob/master/IO/Exodus/vtkCPExodusIINodalCoordinatesTemplate.h
Renamed ti *-impl.h
Adding namespace InSituLib.
InSitu tests are always build now.
VtkMappedMesh should be complete.

Conflicts:
	CMakeLists.txt
	Tests/CMakeLists.txt
Initial implementation of VtkMappedMeshSource.
VtkMappedMeshSource is working.

Remaining todo: point and cell data.
Some comments and cleanup.
Added a mesh conversion round trip test.

It takes an OGS mesh, converts it via VtkMappedMeshSource to VTK, then
the VTK mesh gets converted back to OGS mesh.
Typo.