Happy New Year

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Update getopt_long_only(3) API

- Removes `parseArgc:argv:longOnly:error`.
- Adds `longOnly` (`getter = isLongOnly`) property.
- Adds class initializers (including `+[BRLOptionParser longOnlyParser]`).

Fixes #2:

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Fix getopt_long_only(3) usage

The usage information should print long options prefixed with a single-
(not double-) dash.

Fixes #1.

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Return proper error message for required long-only options

Signed-off-by: Stephen Celis <stephen@stephencelis.com>