Reload when resource fails to load

If the page reload value is not within specific range it will be
adjusted to a default of 10 seconds.

Also adds a link to reload manually.

The page will be reloaded if any of the mandatory scripts/resources
fails to load. The reload will be delayed with exponential backoff
starting from 2 seconds. The retry attempt counter is passed as
'rCounter' query attribute.

config: Disable suspend video by default.

Separate disconnect overlay

The variables in gradle.properties can be overridden on command line like: -Pversion=1.

Reduce the impact of aui, aui-experimental, and jQuery-Impromptu on t…