new: added configuration option to force use of different python binary than environment one.
new: added configuration option to force use of different python binary than environment one.

anru/rsted,amiramix/rsted,tamsky/rsted,anru/rsted,Hasimir/rsted,amiramix/rsted,Egregors/rsted,barseghyanartur/rsted,barseghyanartur/rsted,stefanzweig/rsted-docker,tamsky/rsted,tamsky/rsted,Hasimir/rsted,stefanzweig/rsted-docker,Egregors/rsted,amiramix/rsted,anru/rsted,Egregors/rsted,Hasimir/rsted,stefanzweig/rsted-docker,barseghyanartur/rsted