Some work on demystification of RPG elements

* Added a bunch more ? bubbles with basic explanations of attribute boosts and buffs.
* Added an explicit line in the stats list for bonus from class-matched equipment.
* Added a "Character Build" header to the attribute assignment and class change area.
* Changed the latest "Re-Roll" to "Refund Attribute Points" (so @lefnire will punch me in the face if we ever meet in person)
* Changed display of "Wizard" to "Mage" in stats page and class select modal.
* Changed "Class System Unlocked!" modal header to be more universal, so it still makes sense if e.g. you're changing classes.

Still to do:

* More robust and accurate descriptions of classes.
* More robust and accurate descriptions of attributes.
* Find more places where "wizard" is used and change it over to "Mage".
* Get the mounts count in there? I tried, but the binding wouldn't return anything.