extract DynamicCommand into separate method so it's easier to override and provide your own command class.
alias --help to help on subcommands

When the --help option is present it will change the args array to
include the help command.
Use mime-types 1.x for Ruby 1.8.7 compatibility.
Specify mime-types 1.x for Ruby 1.8 only.
Merge pull request #384 from TimMoore/ruby-1.8.7-compat

Use mime-types 1.x for Ruby 1.8.7 compatibility.
Accept .tt as for templates
Move .tt extension to a constant
Remove unused local vars
Test against multiple versions of JRuby
Add Rubinius standard library gems to bundle
Rename local var
Merge pull request #385 from spastorino/accept_tt_at_end

Accept .tt as for templates
Enforce code coverage minimums
Add RuboCop
Avoid rescuing the Exception class
Prefer loop to literal true in a condition
Use %r for regular expressions matching more than 1 '/' character.
Correct RuboCop offences
revising branch to also inlude the short option

Now the -h and --help enact the same functionality as if help was called
on the subcommand.
remove stray whitespace