Recreate the settings page

[barrykooij]

When creating this plugin I thought it was a fun idea to create an AJAX powered settings page. Should have known these things always end the same, in a refactor.

I've already chatted this over with @remyvv and from what I understood he's willing to do this change :)

What should be done:

• Remove the current AJAX setup.
• Create a default WP settings setup using the WordPress Settings API.
• Maintain backwards compatibility, use the same option name.

[barrykooij]

Related #10 - Once the new setup is done we can simply add a filter to our settings.