Rename Otto to Boxy

[ghost]

Due to unrelated meaning of Otto in some languages I've been forced to change the theme name. Starting from now it is Boxy! It's short, memorable and inspired by gift boxes.

[ghost]

Also I already informed users about renaming and breaking changes caused by it.

[michaelblyons]

To the best of my understanding, this passes all the relevant tests of the Review Guidelines for a package change:

• Old url redirects to the new one.
• Has "Previous Names" in the new package definition.
• Additionally, there is information about the change in the ReadMe and in the release notes of the existing package.

[ghost]

@FichteFoll, sorry for the ping, but I think you skipped this pr, because #5499 & #5501 were closed. Many users are waiting for it, especially newcomers from Best Sublime Text 3 Themes of 2015 and 2016. I'll push 2.0.0 tag, right after closing this pr.

[FichteFoll]

Yes, it appears I skipped this package because your comment 7 days ago disrupted my usual workflow, which is based on github.com/notifications and crawling that from latest update to newest. It seems that you made the comment shortly before I reviewed a larger batch of packages, thus causing the PR to be moved to the beginning of the queue rather than the end where it should have been.

Sorry for that.