removal of an unnecessary recursion, addition of forgotten move, removal of
unnecessary const qualifier, change int to -> size_t

The register class should have explicit constructors, the member variable data should
be initialized in the member initializer list, should be named m_data, and the
finish callback should accept the data by const reference

tailing return type specification caused infinite template instantiation

It really makes no sense to have it inside alib2std component. Moved
into separate tests/ folder.

Remove CMakeLists.txt generator scripts from build phase. Replaced with
CMake's GLOB that can re-run every time the build is invoked. We can
also drop the Python dependency now.

Removed header installs which will be redesigned in future commits.