Fix compatibility with a variety of non-WebGL browsers.

* `template` and `report` were being declared too late for non-WebGL browsers, and they would show no report.
* Added a new section on "WebGL not enabled" which is a different error than "not supported."
* Added a message if JavaScript itself is disabled.
* Request `IE=Edge` so that IE11 without Chrome Frame reports correctly.
* Viewport tweaks for mobile.