excel: Write python-code in a temp-file and execute it.

* ver 0.0.3-beta.3 --> 0.0.4-alpha.1
* docs: Add expected , model-columns for engine-points.
* excel: Track VBA-code in git as separate files.
Properly fit measured_eng_points.

* core: 
** Restructure processor code for readability.
* model: Rename fitted_map --> fitted_eng_map
* model: Rename fitting-params --> coefficients.
* log: Fix log-names.