Merge branch 'master' of https://github.com/ufz/ogs

.travis.yml

FileIO/XmlIO/Boost/BoostXmlGmlInterface.cpp

FileIO/XmlIO/Boost/BoostXmlGmlInterface.h

GeoLib/AnalyticalGeometry.cpp

GeoLib/AnalyticalGeometry.h

GeoLib/Polygon.cpp

GeoLib/Polygon.h

GeoLib/PolylineWithSegmentMarker.h

GeoLib/SimplePolygonTree.cpp

GeoLib/SimplePolygonTree.h

GeoLib/TemplateVec.h

GeoLib/Triangle.cpp

GeoLib/Triangle.h

Gui/mainwindow.cpp

MathLib/LinAlg/Dense/DenseMatrix-impl.h

MathLib/LinAlg/PETSc/PETScLinearSolver.cpp

MathLib/LinAlg/PETSc/PETScLinearSolver.h

MathLib/LinAlg/PETSc/PETScMatrix.cpp

MathLib/LinAlg/PETSc/PETScTools.cpp

MathLib/LinAlg/PETSc/PETScTools.h