Atmos pipes fixes and tweaks

#### Contents

 * Fixed unwrencheable atmos objects' stored pipe being wrongly created on New() because initialize directions weren't set when instanciating

* Fixed constructed atmos objects having a '_stored_' straight pipe , because dirs weren't set on instanciation

_Those fixes, at least, bend pipes transforming into straight pipes on wrench/unwrench._

* Fixed the digital valve pathing in some places (AI should be able to use them now !)

* Pipe colors are now preserved on wrenching/unwrenching

* Various clean-up of unaligned partially connected pipes icons

_This fixes bend pipes appearing as straight pipes when wrenched without connecting to anything._

Carnie's MC Rewrite ___Compatible___.