Functioning canonicalizer for url parameters

* code initially in modules/default.php moved to canonicalizer
for multi-module functionality
* added av.php non-canonical keys
* added publication/module.php non-canonical keys
* added events.php non-canonical keys
* added phpdoc (+5 squashed commits)
Squashed commits:
[e02cc48] some logic fixes
- strips trailing slash
- checks if query string exists
[193b3c7] canonicalization working for feature module
moved most the work to the defaultMinisiteModule class
[a7300a4] more fleshed out canonicalized class
[2f42069] beginning work
[e15744d] skeletal code from Matt at Reason Conference for rel=canonical