Add permission for "vote on own content"

For the record, I'm actually in favor of doing both.

A permission is easy to set up and straightforward, but allowing admins to control if something should be able to be voted on by a specific user is a nice feature. It's not really about altering the permission (which appears to be the reasoning for the request being denied).

Let's say I wanted to prevent nodes from being voted on if its tagged with a term or has some other arbitrary field value, or is older than a specific date. Having an alter hook here would allow for this.