Fixed some warnings under CMake 3.0.0
Merge pull request #425 from bilke/cmake-3-warning-fixes

Fixed some warnings under CMake 3.0.0
made FEMConditions set on meshes non-editable to avoid crash ... this should be fixed based on decision if conditions can be set directly on meshes
activated legacy format for geometry data in debug mode
Introduced new CMake-option OGS_PACKAGE_ADDITIONAL_BINARIES.

This makes it easier to package the OGS File Converter into the redistributable
packages.