pygolang: v↑ (0.0.7.post1 -> 0.0.8)

This upgrade mainly fixes gpython and pymain to be more compatible with
CPython when handling command line. In particular it moves
sys.executable setup and -O handling into pymain:

nexedi/pygolang!10
nexedi/pygolang@21756bd3
nexedi/pygolang@11b367c6
nexedi/pygolang@8564dfdd