CS
Fixed namespace issues
Re-sorted methods, static comes after object methods
Collection is modified by default if there is no result

This way it will be saved to the database when it does not exist
Allow to pass collection to Product::getPrice()

It must not always be the Cart object...
Moved guest cart migration to separate method

Prevents endless loop because the Cart object would not be available
Fixed typing mistake in method name
Set tstamp when adding a new address
Dopped cache functionality for TypeAgent (no longer needed in 3.1.3)
Removed duplicate setModified
Model::setData() was replaced with Model::setRow()
Mark ProductCollection as unmodified once it has been saved
Restored functionality to add address to user's address book on checkout