Add support for only one last `@supportURL` and fix naming standardization

**NOTE**: It appears that Zren is using `.meta` to be the actual metadata block items and so any manipulation of these should be stored elsewhere just in case `collaborators`, etc. is ever used/supported in a metadata block... doubt it will based off of Anthony's prior responses but does make the code simpler to read.

Applies to:
* #174
* #161
Fix missing url from paste op

Applies to #189
Merge branch 'master' into addSupportURLsupport
Fix `@collaborator` to generate the URI properly using `encodeURIComponent`

Output HTML on dev:
* `<a href="/users/%3Ci%3Edoes%20this%20italicize%3C%2Fi%3E">&lt;i&gt;does this italicize&lt;/i&gt;</a>`
... instead of HTML entity escaping
Sanitize `@` keys to prevent malicious use

Applies to #189

* Add sanitize-html for `@supportURL` and `@homepageURL` parts
* Sanitize those urls using a html stub encasement... only push if exactly equal. e.g. don't show if they aren't
* Create html whitelist link json for this since it's used multiple times
* Change affected view page to accomodate changes

Tested on dev okay but needs testing verification
Comply with lack of ES6 compliance in Google V8 dated specifications in node.js and downgrade to ES5 standards, and [our current styleguide enforcement](https://github.com/OpenUserJs/OpenUserJS.org/commit/0263c797d323cdf76be9cd6f11093903ea250b69#diff-ba2dc84c4bcbe54f368b6c7d3bc1b13eR39)

Applies to #189
Add `rel="nofollow` as default unless on current production

* One other bug fix for single `@supportURL` usage... copy/paste goof

Applies to #189
Comply with STYLEGUIDE.md not using unset but declared identifiers and set to `null`

* See [here](https://github.com/OpenUserJs/OpenUserJS.org/commit/0263c797d323cdf76be9cd6f11093903ea250b69#diff-ba2dc84c4bcbe54f368b6c7d3bc1b13eR28)

Applies to #189
Merge pull request #189 from Martii/addSupportURLsupport

Add support for only one last `@supportURL`, fix naming standardization, and such