Global: separate the business logic (math) and the work with the files into different files.

[smirik]

For now, a lot of files have different responsibilities in one module.

An example:

librations_support.f90 has different responsibilities:

1. Math part: bessel functions' calculations, fft e.t.c.
2. Allocating of memory for the structures.
3. Working with aei files & preparing them.

One file should have one responsibility, e.g. math calculation or working with the files. All files should be analyzed based on the Single Responsibility Principle.