Consistent --help and --version flag or commands

[olafurpg]

It would be nice if all combination of help/-help/--help and version/-version/--version were supported. Currently, some of the combinations return error messages.

❯ scala-cli version
0.0.7
❯ scala-cli help
help: not found
❯ scala-cli --version
Unrecognized argument: --version
❯ scala-cli --help
Usage: scala-cli <COMMAND> [options]
Compile, run, package Scala code.

Help options:
  --usage                   Print usage and exit
  -h, -help, --help         Print help message and exit
  --help-full, --full-help  Print help message, including hidden options, and exit

Scala options:
  --js                                           Enable Scala.JS
...