Enabled PETSc 3.5
Changed if-condition for PETSc version according to the suggestion by Nori
use boost::optional as a return value of getMeshNodeIDForPoint()
add a general searching function for any geometric types in MeshNodeSearcher
[bugfix] fixed issue where raster to mesh conversion would fail if all all intensity values were negative
Merge branch 'master' of https://github.com/ufz/ogs
Replace BaseLib::number2str with std::to_string.

Also remove the header StringTools.h everywhere.
Add a previously missing sstream include in DateTools.cpp.
[GeoLib] Another version for GEOObjects::getGeoObjects().

The commit is a preparation to access GeoObject objects via the geometry
name and the object name (patch name).
Merge pull request #448 from TomFischer/GeoLibGetGeoObjectsByName

[GeoLib] Another version for GEOObjects::getGeoObjects().
Merge pull request #456 from endJunction/StdToString

Replace BaseLib::number2str with std::to_string.
Added one more condition for PETSc versions
Merge pull request #450 from wenqing/forPETSc35

Enabled PETSc 3.5
add explicit and assignment operator to DenseMatrix
add NewtonRaphson
add tests for NewtonRaphson
Declare and init vars in same place.
Add spaces around operators.
fix copyright
Merge pull request #31 from endJunction/add-Newton

Add newton
[ML] MeshQuality/RadiusEdgeRatioMetric: Remove unused variable.