cdn 6.x-2.0-rc6

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

1. ✓ significant expansion of functionality
2. ✓ awesome UI
3. excellent documentation, including high-quality screencasts

IMPORTANT NOTE:
The Drupal core patch has changed in beta 6 (not in this RC)! So, before updating, revert the patch of beta 3 (or from beta 2, if you're upgrading from beta 2). Then update the code. Then apply the new patch.

Changes since DRUPAL-6--2-0-RC5:

• Fixed #957774: Fatal error: Call to undefined function _cdn_advanced_get_db_connection() in modules/cdn/cdn.module on line 358 (only occurs when using File Conveyor mode)
• #970632 by ahwebd: Add "image_captcha" to default blacklist
• Fixed #972344 by wimleers and intoxination: Fallback integration method breaks some image tags (attributes before the src attribute are lost)
• Fix UI string.
• Revised the README for better legibility.
• #974992: File extension filtering in Origin Pull mode is case-sensitive
• #971712: Rewrite image URLs in the node body