dev: Modified the run script to make it cleanup child processes after run
dev: Modified the run script to make it cleanup child processes after run

This commit modifies the run script to add code that captures the
PID of the test server and the PGID of the xvfb process group so that
it can kill these child processes after the script has run.

QQuick/Transcrypt,QQuick/Transcrypt,QQuick/Transcrypt,QQuick/Transcrypt,QQuick/Transcrypt