Fixed rendering of partially transparent facades

This should finally fix issue #1468

Essentially the issue with the previous attempt was that opaque blocks (pipe, the facade connectors, and opaque facades) were rendering in the pass meant for semi-transparent blocks, which caused the clipping issues. What I've done is ensure that all opaque things (gates, pipes, etc) are only rendered in the opaque pass, and facades regulate rendering to the proper pass as needed.

![](http://puu.sh/82Uq1.png)

![](http://puu.sh/82Uqw.png)

![](http://puu.sh/82VfJ.jpg)
The facade on the right there is packed ice, demonstrating solid and opaque facades in one block space