Rename and clean up

[johnd0e]

Currently in the project there are some inaccuracy and inconsistency with naming of files/plugins.

E.g.

• All highlighters are named as portal-highlighter-....user.js, with 1 exception: show-portal-weakness.user.js
• Mistypes in portal-highlighter-needs-recharge.user.js, portal-highlighter-forgotten.user.js
  names contain 'hightlight' (#798).
• Several deleted plugins still has stub-files.
• max-links.user.js is actually Tidy Links in layer chooser.

We care for stubs and names for 1 reason only: (auto)updating.
But:

• Our fork is still young, we could afford some changes
• Update was broken anyway: Scripts updateURL/downloadURL should not be empty #32

So I propose to make some improvements until it's too late.

[johnd0e]

So I'm going to rename some files, change some plugins names and categories, and remove old stubs for deleted plugins.

What is important for updating:

• Filename, as it is in the @updateURL/@downloadURL
• @name (and @namespace, but it's consistent for every plugin in this repo)
• @version (Scripts versioning #99)

What is not important, and can be changed freely:

• @description
• @category
• @id

AFAIK, @id is not used neither in the IITC itself nor in any script manager, so I'm going to get rid of this field completely.

Thoughts?