OpenSCAD multi part render script

This is a simple method of defining multiple output files in an OpenSCAD script and a shell script to render them. Where this is useful:
* The view you're editing in is different than what you want to print in
* You want to draw in 2D but preview in 3D
* You are building a model with several pieces that should be exported separately
* You want to render in a higher resolution than you preview in

How to use:
* Download render_scad.sh, make it executable, place it somewhere in $PATH
* Look at test.scad for reference and place the relevant if statements in your scad script. The custom names you check for MUST end in .stl or .dxf.
* Call render_scad.sh file.scad
* Output files are always placed in the same directory the scad file is in