This change makes it possible to type the beginning (the prefix) of a
command name and rebar will guess the full name of the command,
thereby saving the user precious keystrokes. As long as the prefix
matches only one command, rebar runs that command, otherwise rebar
prints a list of candidate command names. The "-" character is
considered to be a word separator and the prefix matching is done per
word.
Example prefix matches:
co ==> compile
cl ==> clean
create ==> create
create-a ==> create-app
c-a ==> create-app
c-app ==> create-app