add support for single-letter option chaining

[wibbuffey]

e.x. ls -lah instead of ls -l -a -h

[wibbuffey]

hmmmm..... but this would remove support for GCC-style options (e.x. -Wpedantic). we'd have to add an extra parameter, which would require a new major release (or we can just set a default and have a new minor release). either way it will take lots of work