Rename the `e` function to `dancepill`

People may have other commands aliased to `e` already. This keeps the original
usage intact (source dancepill/e; e package.tar.gz) while allowing people to
re-alias `e` to something else and keep a hold of the original dancepill
function.
Merge pull request #2 from tomassedovic/namespacing

Rename the `e` function to `dancepill`