Reorganization of the apollon.tools

[Teagum]

The tools module needs reorganization. Currently it includes function for statistics, IO, assertions, and array indexing. The idea of the tools module was to have a common place for functions that are shared between packages. As far as I can see, none of the functions in apollon.tools is used in more than one module. It is simply a mess.

As a first step, you have to check wether the functions in a apollon.tools are actually in use. fsum, for example, was part of a failed attempt to improve array sum accuracy. Unused functions shall be removed.

You then have to move each function to their corresponding module/package. For functions really could be used in different modules, check if it is worth the create a new module.