configure process kill timeouts through environment with fallbacks
configure process kill timeouts through environment with fallbacks

remeeting/baseimage-docker,phusion/baseimage-docker,phusion/baseimage-docker,jedisct1/phusion-baseimage-latest,remeeting/baseimage-docker,REDDOXX/baseimage-docker,jedisct1/phusion-baseimage-latest,StepsAway/baseimage-docker,StepsAway/baseimage-docker,REDDOXX/baseimage-docker