Bring request back. Let's fix it.

This reverts commit 6bc6b46a94cd9014534d4649a1d35b82b4bba44e.
Avoid downloading deps on postinstall for GH-42.

Skip dependency installation entirely if the `dep` directory
already exists.
Merge branch 'dependency-free-postinstall'
Require onyx@0.1.5 for Node 0.8 and 0.10 support.