cdn 6.x-2.0-beta2

The goal for 2.0 is simple: make the CDN integration module kick ass. This will be done in four ways:

1. significant expansion of functionality
2. awesome UI
3. excellent documentation, including high-quality screencasts
4. streamlined process to integrate with a specific CDN (if the CDN providers want to sponsor this at least)

Changes since DRUPAL-6--2-0-BETA1:

• Fixed two potential divisions by zero.
• Follow-up commit for #516188: .js files should still be among the default extensions for basic mode.
• Ensure the patch file still exists before attempting to verify it's been applied.