scripts/run: Always kill java instances

Executing two instances of this scripts simultaneously caused a race
condition resulting in both scripts attempting to launch servers. This
fixes this by always attempting to kill other servers, along with other
instances of the target script.
scripts/run: Don't export DEBUG until runtime

This means that we're not running the test suit with the DEBUG env
variable set.
download: Use button group for file format

Issue #271.
download: Remove redundant JavaScript

Issue #270.
download: Set the input group size

Issue #271.
js/download: Set the button text

Issue #271.
build/Documentation: Build marg silently until fail
Merge branch 'issue/271'