Merge strict eolian type checking branch.

In this branch I turned on strict eolian type checking and silenced all
of the errors that came to be because of it (fixed some).

I did it so new code will not introduce new errors. We've had more
errors introduced recently, and I believe it's because of ignorance. No
more excuses, compilation will now fail if you fail to handle types
correctly.

We need to fix my workarounds. Many of the .eo files that I worked
around on need to be removed anyway, and a lot of the rest need a lot of
changes, so there was no point wasting my time into fixing it properly.