Merge pull request #223 in VECTO/vecto-sim from...

Merge pull request #223 in VECTO/vecto-sim from ~EMKRISPMI/vecto-sim:feature/VECTO-289-new-optional-component-angle-drive to develop

* commit '51457e73': (63 commits)
  restored menu items in main window, changed button sizes in file browser (again)
  updated open icons and button sizes in VectoAux
  user manual html updated
  vs project file with new test files included
  corrected component count in test
  updated vmod test files to new format (including P_angle_in, P_angle_loss)
  corrected error in cycle type check in PowertrainBuilder
  added test for angular gear losses
  error message
  added test with and without angle gear with loss map or efficiency
  usermanual: modfile added P_angle_in, P_angle_loss
  user documentation: added powertrain structure
  added new icons for GUI
  removed angular gear for one of the generic vehicles to test
  added missing files for engineering mode generic vehicle 12t
  add angular gear only if needed, adapt JSON input that angular gear is optional
  removed hamster-code
  minor adaptions gui (button positions)
  file browser dialog with icons
  better file browser dialog in GUI
  ...