Merge branch 'type-correctness' into 'master'

src/OpenVolumeMesh/Attribs/ColorAttrib.hh

src/OpenVolumeMesh/Attribs/ColorAttribT.cc

src/OpenVolumeMesh/Attribs/NormalAttrib.hh

src/OpenVolumeMesh/Attribs/NormalAttribT.cc

src/OpenVolumeMesh/Attribs/StatusAttrib.cc

src/OpenVolumeMesh/Attribs/StatusAttrib.hh

src/OpenVolumeMesh/Attribs/StatusAttribT.cc

src/OpenVolumeMesh/Attribs/TexCoordAttrib.hh

src/OpenVolumeMesh/Core/PropertyHandles.hh

src/OpenVolumeMesh/Core/PropertyPtr.hh

src/Unittests/unittests_basics.cc

src/Unittests/unittests_files.cc

src/Unittests/unittests_properties.cc