[Cleanup] Normalise include guards

dune/tectonic/body.hh

dune/tectonic/ellipticenergy.hh

dune/tectonic/frictiondata.hh

dune/tectonic/frictionpotential.hh

dune/tectonic/globalfrictiondata.hh

dune/tectonic/globalnonlinearity.hh

dune/tectonic/globalruinanonlinearity.hh

dune/tectonic/gravity.hh

dune/tectonic/localfriction.hh

dune/tectonic/minimisation.hh

dune/tectonic/myblockproblem.hh

dune/tectonic/mydirectionalconvexfunction.hh

dune/tectonic/tectonic.hh

src/assemblers.hh

src/boundary_writer.hh

src/enums.hh

src/explicitgrid.hh

src/explicitvectors.hh

src/friction_writer.hh

src/sand-wedge-data/mygeometry.hh