plugin-admin-notes needs to clean up it's own mess when uninstalled.

[binarygary]

We can close #35 as the PR was merged.

This issue is related to what this plugin is uninstalled (removing the posts and meta and lock/autoupdate options).

[binarygary]

Please test PR #39
It should remove all settings when the plugin is uninstalled.

If it's found to work correctly, please merge the PR and close this issue.