Fix WebGL signatures.

[mseddon]

Fixes a few issues with the type signatures of some WebGL calls:

polygonOffset was (Int, Int) => Unit, rather than (Double, Double) => Unit
lineWidth was (Int) => Unit, rather than (Double) => Unit
texParameterf was (Int, Int, Int) => Unit, rather than (Int, Int, Double) => Unit

Also cleaned up some incorrect parameter documentation, and further clarified internalformat/format.

I also tried (uncommitted) to prevent some scaladoc warnings in this file of the form "Could not find any member to link for "Float32Array", but for some reason (possibly because it's external to scala-js-dom?) even fully qualified names still issue a warning. If anyone has any idea how to handle this correctly, I'll combine that into this PR, too, since this file got a little shouty since the introduction of scalajs.js.typedarray.

[sjrd]

Shouldn't this be renamed to format instead of removing it?

[sjrd]

And in general, there seems to be many removals that should have been renamings instead.

[mseddon]

Whoops, I got a little carried away there...

[sjrd]

OK for the actual signature changes. These should be in a different commit than the documentation fixes, since they have nothing to do with each other.
You can easily recreate your commits first with git reset HEAD^ (removes the top commit but keeps its changes, in the working copy) then git add -p (allows you to stage parts of the working copy to create a commit).

[sjrd]

LGTM

[mseddon]

Any ideas on the scaladoc warnings, or should we just ignore them for now?

[sjrd]

Ignore them for now. I think there is something that needs to be done about linking different ScalaDocs with each other, but I never really understood how that worked. Anyway it's worth a separate PR.

[mseddon]

Alrighty. Ta!