Duplicated nodes should be allowed to support zero volume elements

Add two mesh edit tools: reverse node ordering, remove elements

Removed method makeNodesUnique().

Change ogs5msh fileio

Fix for always adding OGS files to Recent Files menu

Fixes an error where OGS files were not added to Recent -=Files=- menu when they where opened from a tree view.

Fix a bug that precision given in Writer() is unused  in VTU output

Small pull request to fix warnings.

Advanced geo to mesh mapping

Isoparametric finite quad4 element.

Small change in FileIO and some new methods in BaseLib.

Use it in the NumLibFemIsoQuad4Test instead of auto.