remove redundancies; add comment;
remove old method 'plot_n_tex' and add plot options to new method
'plot_assess_value'
clean_up; remove old evaluation cases, i.e remove 'eval_mode' ==
'massivbau' and 'eval_mode' == 'sig_princ_dir_level-1';
minor renaming (index '_sig_up' changed to '_sig1_up' etc.)
calculation of 'alpha_sig1' and transformation of stress resultants
based on Mohr-circle formulas with positiv z-rotation; minor renaming
and cleanup ('_deg')
unchanged
unchanged (only uncomment)
add plot options 'scale_factor'
specify 'strength_characteristics' in 'LCCTableULS' call