black oil writer: fix typo
FindQuadmath.cmake: pass -fext-numeric-literals to the compiler if it is supported

newer compilers (GCC >= 4.8) need this in C++-2011 mode to support
quadruple precision math...
quad.hh: bail out if the file was included after dune's classname.hh

if the order is the other way round, the linker will throw an error,
so it's better to produce a more explicit error message...
ECL problem: make it compile with Scalar != double

opm-parser always returns vector<double> as data fields...
FV discretizations: make them work with Scalar == quad
fix build on dune 2.2