Nodes require docker --link

[androa]

The NodeBase/entry_point.sh checks for the environment variable $HUB_PORT_4444_TCP_ADDR, but executes selenium server hardcoded with http://hub:4444/

This makes it hard to run the images in any orchestrating frameworks, as most of them does not manipulate the hosts on the containers (or use dockers link feature).

[mtscout6]

Closed by #12