Generous matching of --version, --help

[edemaine]

Fixes #1254 (without yet addressing #1258).

Potentially controversial: Ties up -h and -v. I could instead just add -help and -version. Some languages such as Python and Rust use -V for version, so we could instead opt for that.

[STRd6]

-v and -h are fine for help and version.

I dislike -version and -help but it's probably fine. I'd also rather just accept it since we know what the user means rather than say something less helpful like "Did you mean --version?"

[bbrk24]

Of other compilers I tested, when given -version:

• Clang said "Did you mean '--version'?" and not much else
• Swift, Java, and Perl printed their version info as if given --version (For some versions of Java, only -version works and not --version)
• Everything else gave some form of unrecognized flag error.