Generate correct file name with package command.
Add gnu as source.

Emacs-23 needs this because some dependency to Cask requires cl-lib,
which is only available in the gnu elpa source.
Merge branch 'add-gnu-source'
Fix type error

Cask Package wants a string as package name, so we must convert our EPL
package symbols.
Make sure EPL uses symbols as package names
Fix indentation
Merge pull request #98 from cask/package-use-name

Generate correct file name with package command.
Remove useless comment.
Do not use local cask in Makefile.
Add cask bin dir to path on Travis.
Commander has print usage and exit function.
Install cask and add to path in before install.