Enable doxygen for MeshGeoToolsLib.
[MeshGeoToolsLib] Base class for search length algorithms.
[MeshGeoToolsLib] Heuristic search length.

Computes the search length using a heuristic.
[MeshGeoToolsLib] Impl. of fixed search length.
[MeshGeoToolsLib] Using search length in MeshNodeSearcher.
Using new MeshNodeSearcher interface in Tests.
Using MeshNodeSearcher interface in BoundaryCondition.