All changes below are by Andreas Zenner but I moved his comments
from a separate text file into the FDM file.
* MiG-15bis.xml: make the FDM more realistic.
* MiG-15bis-set.xml:
- tweak the view configuration
- add tweak factors and initialization for the new FDM.
* Models/Liveries/CSSR_aerobatic.xml: add documentation.