Added saveComment - #18

I'd like some input from @pippinsplugins or @rmccue before we merge this one.

Also, please update using the WordPress coding standards. Currently there are spaces missing from around parameters within parenthesis.

I readjusted the code to meet standards, sorry was kind of rushing as my application already had commenting. Will be adding delete shortly.

+1 on adding a comment endpoint, but we need heavy levels of sanitation and permission checking, so 👎 on the code as it stands.

Added in a new /users to pull all users, POST to add new user, and /user/:id to grab a single user

-1 on this PR. Separate features should be pulled into separate pull requests to ensure we're as modular as possible, plus it appears that there's merge/rebase artifacts in the PR.

That said, these would form a nice base for widget/user endpoints. I'll review these and rewrite when I'm back to full capacity.