is_same_v<> for is_same<>::value
decay_t<> for decay<>::type
is_integral_v<> for is_integral<>::value
invoke_result_t<> for invoke_result<>::type

To access the solution values a dof tables are passed
too.

Fixes multiple copyright messages in the doxygen docu.

ag '\\file' -L --ignore=ThirdParty *Lib |xargs  sed -i 's/\(.*\)\\copyright/\1\\file\n\1\\copyright/'

Clang format run on near-the-header lines.

Happy New Year

The least squares extrapolation proceeds component-wise and produces
vector-valued fields.

Now time, current solution and the process DOF table are passed to the
extrapolation routine, enabling more versatile nodal output
possiblities.

* no property tags anymore
* no templates anymore in the implementation
* all template use is in the adaptor class