Language evolves and spelling changes. Words like these often get merged. For example you won't see to-morrow these days but it was the normal spelling of tomorrow. Also email used to be e-mail, internet until recently was Internet. But of course you can still use e-mail and Internet, but not to-morrow.
Basically your case is consistent with how these changes happen.
- name calling
Like an evolution. The first and the second are the "standard" spellings but English is flexible enough to allow the third one already, and in time maybe (probably) that will be the most widely accepted.