Add STL export.
Edit stl test export.
More test models.
Fix to endloop tag in STL writer.
Add a default facet normal to STL output.
Add vertex flag to STL writer.
Add a library for STL writing. Convert to using binary writer.
Add a normal to STL output.
Try with text writing again.
Revert to the original text based STL method.
Remove the STL library and binary method.
Add stadium STL model.
Test diff of stadium model.