Support multiple quizzes for a single CME front-matter

Required for Rap. This significantly alters the database design and all the pages, tools and admin components. Some vocabulary is updated to match reality.

See https://docs.google.com/a/silverorange.com/drawings/d/1XfdUBOcMju1xudWNFsrDqzf-hCm7fmCgmrC2SmrpMRY/edit for the new database diagram.

 * CMECreditType becomes CMEProvider
 * CMECredit becomes CMEFrontMatter
 * CMEFrontMatter contains an evaluation and the attestation content
 * CMECredit is a new object with hours and a quiz. CME-specific quiz features are also moved to this table instead of the Inquisition table
 * AccountEarnedCMECredit is a new binding for earned credits so we don't always have to query an entire quiz response to display earned CME credits
 * AccountCMECreditBinding becomes the more descriptive AccountAttestedCMEFrontMatter and an attested_date is added

Requires silverorange/Inquisition#9
Seeing as `CmeOptionHelper.php` is no longer abstract, I wonder if we should make `CmeQuesitonHelper` concrete as well. This is the only abstract method, and could logically be set up for most sites by just doing the following

```php
// {{{ protected function getCreditNavBarTitle()

protected function getCreditNavBarTitle()
{
	$title = sprintf(
		Rap::_('%s Credit'),
		$this->credit->front_matter->provider->title
	);
	return $title;
}

// }}}
```