setAttribute expects a string, not a number.
Rename fields to match current naming style.
Fix check for undefined 'window' global var.

May be necessary if not running in a DOM environment.
Exit function earlier if possible.
Remove 'private' resize function from TypeScript declaration.

This function is called automatically within the render loop. There's no
use case that I can see for it to be called by users of the library.
Therefore I'm removing it from the TypeScript declaration file, which
should only contain public members.
Hoist method documentation and add TODO.
Bump version to 1.26.0.