METEOIO dependence if code is compiled with METEOIO OFF

[cozzini]

When we compile with meteoIO off we should not need/compile the meteoio plugin and link against MeteoIO library.

[asartori86]

Our data-structures GeoMatrix<T> and GeoTensor<T> are directly derived by meteoio data-structure

template <typename T>
class GeoMatrix : public mio::Array2D<T>

template <class T>
class GeoTensor : public mio::Array3D<T>

so unless we rewrite these classes we cannot avoid to compile and link against the meteoio library

[cozzini]

Ok this means we should use these structure everywhere.