Revert "auto_width: allow range of values"

This reverts commit 3dc2186f9c1eee2149d46e728ffc0d0548ffd8fb.
Use module pattern for JS code
Further conversion to module pattern
Request only 350 pixel height by default
If in viewer panel, auto-size to fill window
Simpler access for self.opts
Remove auto_width and add smart_size option
Correct auto-resizing behavior