Doc: Correct module name in examples
Fix description-from-readme extraction
Don't leak globals
Be stricter about URLs being required where expected

Also, normalize github repos using the gh url parser
package: Use isaacs fork of github-url-from-git

At least until https://github.com/visionmedia/node-github-url-from-git/pull/2
is accepted.

Saves a few unnecessary deps from being installed
Merge pull request #18 from isaacs/master

A whole bunch of fixes from Isaacs.