get rid of transient properties when not needed

various HUD improvements

Merge branch 'master' of https://github.com/20tab/UnrealEnginePython

added create_transient_texture()

added bind_on_request_progress to IHttpRequest

fixed a typo in preprocessor for the sequencer

fixed python editor on 4.12

fixed 4.13 support

fixed factory-create_new

Merge branch 'master' of https://github.com/20tab/UnrealEnginePython