Require coffee-script/register for coffee 1.7.x.

In coffee-script 1.7, the default module no longer registers a require handler due to require.extensions being deprecated: http://nodejs.org/api/globals.html#globals_require_extensions

Thankfully, we can just require coffee-script/register instead, and it restores this behavior (by using the deprecated API… ehhhh).
Merge pull request #1 from adunkman/coffeescript-require

Require coffee-script/register for coffee 1.7.x.