Update libexec/sub-help

Allow colors in summary view (using ANSI Escape Sequences). 
Example here: http://d.pr/i/3yyn
sub-help: better use of awk, grep, and sed
prepare.sh: turn two calls of sed into one
Allow sub names that contain a dash

Replace dash with underscore to allow sub names that include a dash
e.g. "sub-admin".
Merge pull request #10 from Youpinadi/master

Allow colors in summary view
Merge mlafeldt/awk-sed-grep. Closes #15.
Merge pull request #17 from z0mbix/master

Allow sub names containing dashes
Better formatting for sub-help thanks to @sstephenson
Deal with bash/zsh stupidness and subs that may have no letters in the name
Rename _sub_complete to _sub_wrapper since it really has nothing to do with completion