Only istream is required here.

This avoids another half of the deprecated warnings associated with the implicit
copy assignment in presence of user defined ctor.

Clang reports:
warning: definition of implicit copy constructor for 'TemplatePoint<double, 3>'
is deprecated because it has a user-declared destructor [-Wdeprecated]

Update documentation.

Extend the input to arbitrary TemplatePoint,
but it is working only for TemplatePoint<double, 3>
== Point3d for now.

The lexicographic comparison is now working for
arbitrary TemplatePoint dimensions and underlying
floating types.

... into TemplatePoint header file.

Using the removed constructor was insecure because there was neither a
compile time check nor a run time check if the size of the C array holds
enough data.

Try to fix some failing tests on travis CI for Vector3 associated to default constructor of Vecor3.

Changed also
- the data type that holds the coordinates from pure C array to std::array<T, DIM>,
- the implementation of write() and read().

- Implemented class template GeoPoint (see GeoLib/Point.h) and substituted class templates in the typedef.
- Some changes due to changed namespace in MathLib/Vector3.h and GeoLib/Color.h.