Fix #92: Drop support for useless optimize option

[Mingun]

There no reasons for use value other than speed.

CLI option and definition in .d.ts are left for backward compatibility

[hildjj]

I was assuming we would go ahead and rip the functionality out of generate-js also?

[hildjj]

This looks good. One last thing to discuss. Should we issue a DeprecationWarning for people that use "size" through the API? It would be nice, but I don't want to have to mock process.emitWarning in the web build.

[Mingun]

Not enough @deprecated comment in the .d.ts? I think, that modern users would, at least, use typescript types and should see that warning.

[hildjj]

I'm more worried about the non-modern users here, I think, but I see your point. Let's land this then be on the lookout for issues that get filed if people are confused. I think we should land this now since I want to rebase other changes on top of it. Make sense?

[Mingun]

Make sense.

[StoneCypher]

Not enough @deprecated comment in the .d.ts? I think, that modern users would, at least, use typescript types and should see that warning.

This isn't how typescript works.