Changed directory structure to support Sparks package management.

The directory structure was changed around in preparation to support
the Sparks package management system for CodeIgniter (http://getsparks.org).

**The following things took place in this commit:**
* Move all contents of the application/ directory up one level.
    -1config/ controllers/ helpers/ language/ libraries/ models/ views/
    - Left captcha/ alone... Not quite sure where to put it yet.
    - Delete the now-empty application/ directory
* Create vendor/ folder and move phpass into it.
    - (phpass is now in vendor/phpass-0.3/)
* Change libraries/Tank_auth.php to reflect the new path of the phpass library
* Add spark.info
    - Spark package management system requires this to work properly