Merge remote-tracking branch 'origin/feature/8005_remove_pythonapi_preference_checkbox'
Merge remote branch 'origin/feature/7984_remove_indirect_trans'
Merge remote branch 'origin/feature/7019_cpp_runpythonscript'
Merge remote branch 'origin/feature/6875_remove_deprecated_pythonalgs_key'
Re #8011. Remove majority of contents of WinInstaller directory.

This mostly relates to the old way of building Windows installer packages.
Now it's all done with CPack. Just a few things remain that are pulled in
by the CPack packaging.
Merge branch 'feature/8011_clear_wininstallers_directory' into develop