Miscelaneous improvements

[rbrito]

Hi.

The code for enjoyreading is in a very bad state and I started working a little bit on it. Some of the commits here are janitorial, some are functional. My commit messages are a bit on the verbose side, explaining why I am taking a given decision.

Unfortunately, it seems like a huge amount of effort is needed to bring this extension up to shape (and some static analysis tools are badly needed here).

I think that with the right amount of focused effort, we may get it to be offered on addons.mozilla.org.

I am badly interested in anything that improves the readability of some sites, since I have very poor eyesight and working on an extension is a good excuse to learn some javascript and some creation of extensions.

Please, review and consider merging these commits.

Thanks,

Rogério Brito.