Rework site to show the two-factor usage method

This pull request changes the columns from 

    Site | Docs | SMS | Google Auth | Authy | VeriSign VIP | Custom

to

    Site | Docs | SMS | Phone Call | Email | Hardware Token | Software Implementation

![Imgur](http://i.imgur.com/F6Kj0n7.png)

See [PR #320](https://github.com/jdavis/twofactorauth/issues/320) and [PR #208](https://github.com/jdavis/twofactorauth/issues/208) for more context about these changes.

I updated every `.yaml` file; anywhere there was a `Yes` for `authy` or `goog` or `verisign` there should now simply be `software: Yes`. For `custom` entries I added the appropriate `hardware` or `software` entry. I visited every `doc` link and tried to capture the data, but I welcome the community to fix anything I missed. I also removed stray white space and capitalized `Yes` and `No` where appropriate.

I think it turned out well.

---

Now that I've done all this work, I have a new idea that might be cleaner:

    Site | Docs | Implementation

We then place the appropriate icons for each of the five categories. Perhaps

    SMS: mobile icon
    Phone Call: phone icon
    Email: mail icon
    Hardware Token: lock icon
    Software Implementation: shield icon

Here's what that might look like:

![Imgur](http://i.imgur.com/RH6UwAy.png)

See PR #334 for the code.