Engine room facelift (?)

Attempts to balance the following aspects of the engine room:
* The ability to change waste canisters without entering the engine room
* Not running pipes under reinforced walls
* Security

The bolts and blast doors on the west side are controlled by the nearby buttons and have ID-requirements.
There are pumps under said blast doors.

The current result: 
![Engine Room - Try 3](https://www.dropbox.com/s/mkgb64seujrp4l7/Engine%20MKIII.png?dl=1)

Why filter at all when it's currently possible to let superheated gases straight into the atmos scrubber pipes by filtering nothing? Well, I've heard it makes atmosphere technicians very upset.