Auto merge of #670 - tormol:parse_nonascii_usage, r=kbknapp
Auto merge of #670 - tormol:parse_nonascii_usage, r=kbknapp

Handle non-ascii names / options in from_usage().

Closes #664 and should make it faster too.

Why aren't the stop_at functions written like `c != a && c != b`?

clap-rs/clap,kbknapp/clap-rs,clap-rs/clap,clap-rs/clap,kbknapp/clap-rs