Move to a plain node API and add Grunt wrappers for tasks

Removes the target task.
Resources: Remove early check for no resources

This was unnecessary and actually created a situation where a site with
existing resources that removes all resources would end up not unpublishing
the existing resources.
Taxonomies: Remove duplicate parsing of taxonomies.json
Fix context of callbacks
Force context for most callbacks
Move createChecksum to the prototype
Build: Upgrade to grunt 0.4.5
Update tasks to Grunt 0.4 API
Fix context in validateTerms()