Get rid of outdated functions in Constants.*

[BenjaminRodenberg]

The following functions are not really useful anymore:

precice/src/precice/Constants.hpp

Lines 9 to 13 in e480aef

	const std::string& nameConfiguration();
	const std::string& dataDisplacements();
	const std::string& dataForces();
	const std::string& dataVelocities();

We can get rid of them. Don't forget to also remove them in the bindings.

[uekerman]

I would actually go one step further and remove Contants.hpp completely.

precice/src/precice/Constants.hpp

Lines 15 to 18 in e480aef

	const std::string& actionWriteInitialData();
	const std::string& actionWriteIterationCheckpoint();
	const std::string& actionReadIterationCheckpoint();
	const std::string& actionPlotOutput();

... could be moved to SolverInterface or we replace them by better solutions

precice/src/precice/Constants.hpp

Lines 20 to 21 in e480aef

	int exportVTK();
	int exportAll();

... I don't know what this is for

[uekerman]

I think nobody uses actionPlotOutput

[BenjaminRodenberg]

I think nobody uses actionPlotOutput

I tried to remove it, but then I got into trouble:

[ 65%] Linking CXX executable binprecice
libprecice.a(SolverInterfaceImpl.cpp.o): In function `precice::impl::SolverInterfaceImpl::initializeData()':
/home/benjamin/precice/src/precice/impl/SolverInterfaceImpl.cpp:321: undefined reference to `precice::constants::actionPlotOutput[abi:cxx11]()'
libprecice.a(SolverInterfaceImpl.cpp.o): In function `precice::impl::SolverInterfaceImpl::finalize()':
/home/benjamin/precice/src/precice/impl/SolverInterfaceImpl.cpp:442: undefined reference to `precice::constants::actionPlotOutput[abi:cxx11]()'
libprecice.a(SolverInterfaceImpl.cpp.o): In function `precice::impl::SolverInterfaceImpl::handleExports()':
/home/benjamin/precice/src/precice/impl/SolverInterfaceImpl.cpp:1540: undefined reference to `precice::constants::actionPlotOutput[abi:cxx11]()'
collect2: error: ld returned 1 exit status
CMakeFiles/binprecice.dir/build.make:244: recipe for target 'binprecice' failed
make[2]: *** [binprecice] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/binprecice.dir/all' failed
make[1]: *** [CMakeFiles/binprecice.dir/all] Error 2
Makefile:162: recipe for target 'all' failed
make: *** [all] Error 2