Add support for humans.txt/author relations.
Merge pull request #185 from bramstein/bs-rel-humans

Add support for humans.txt/author relations.
HtmlShortcutIcon.attach: Default to put put the <link> node at the end of <head> if no position/adjacentRelation is specified.
1.6.22
Css.prototype.inline: Fixed test for whether the node is already <style> rather than <link rel="stylesheet">
1.6.23
Degrade all errors to warnings.
Removed the dieOnError option now that 'error' events are no longer emitted.

This was introduced at a time where anything unexpected was emitted as an 'error' event, which is no longer the case.
1.6.24
flattenRequireJs: Comment out a test that sometimes fails due to a race condition. The code it's testing is about to get rewritten anyway.
Whoops, errors passed to 'cb' by a transform should still be emitted as 'error' events.
asset.urlOrDescription: Make the url relative to the root of the AssetGraph instance if possible.
asset.urlOrDescription: On second thought, make file:// urls come out as file system paths relative to CWD.
1.6.25
Fixed stupid typo that broke everything.
1.6.26
package.json: Sorted devDependencies alphabetically.
Convert the addCacheManifest test to mocha/unexpected.
Converted Asset test to mocha/unexpected.
Update jshint to 2.5.0.