Use the style of pkg-annotate.8 for long options

   -- blank line between long and short option synopses

   -- indicate mutually compatible flags by --{opt1,opt2,opt3} 'any of'

   -- indicate incompatible options by --{opt1|opt2} 'one of'

Sort options.  Other minor fixes.
Document long options
Document long options
Document long options.

Sort options.
Document long options

Minor fixes
Document long options

Sort options
Document long options
Uh, yeah.  It's 2014 already.
Document long options
Document long options
Document long options
Fix spelling
Document long options
-r long form better expressed as --required-by rather than
 requirements.
Document long options

Add mising -p / --prefix to synopsis
Document long options
Allow pkg lock -l or pkg unlock -l to list locks with out actually
(un)locking anything.
Document long options
--read-file -> --file for consistency
Document long options