This reverts commit 07cc55d9

This reverts commit 211fa521, reversing
changes made to 8ba56d73.

full pass on the documentation to clarify general concepts, introduce the API and mention the new algorithms (including parallel features)

This reverts commit 721727e3

square_cgns.geo
flow_around_circular_cylinder.geo
cube3d_27blk.geo

Use the "AnalyseCurvedMesh" plugin to analyse the resulting mesh. It should now fail as the quality will be far too low.

Addition of test which now fails to generate a mesh due to using the meshGeneratorPeriodic instead of the meshGenerator algorithm. The fix will be committed later.

Addition of project to show the problem. A warning will be given during meshing: "Meshing surface 1: 2 elements remain invalid". I hope the build server will reject this case due to this warning message. However, as the SICN quality is very poor for case (minimum value is 0.002) and will be much larger with the fix (>0.4), I would also like to check on this but this does not seem to be possible from the interface (using the plugin AnalyseCurvedMesh does not create a new view from which we could pick the minimum value).

Addition of test to illustrate the problem: existing node is not recognized as distance is larger than the tolerance used.

Addition of forgotten mesh statement. Without this the mesh command is not executed yet and so the number of triangles will never be more than 0. However, looking at the build server, if first gave errors and warnings for this test case which are now gone with the fix of the previous commit. This commit should make the test pass.

Addition of test to catch the problem: surface consists of cylinder with 3 loops: an outer loop and two inner loops intersecting each other on the seam of the cylinder. The test should now fail as I haven't committed the fix yet.

- added createTopology and createGeometry in api
- renamed symmetry (symmetrize), homology (computeHomology) and cohomology (computeCohomology): all api functions should be verbs

As extrusion already generates volumes, there is no need to generate this volume explicitly. It will now only result in two equal volumes, causing an error about a void region.