bugfix: division by zero can cause malformed primitives
Testcase and fix for a problem transforming an empty bbox with very small numbers in a transformation matrix
Revert "Fixed an issue which caused us to traverse the entire tree for OpenCSG rendering traversals, where we didn't actually use the traversal results (for all nodes requiring CGAL)"

This reverts commit 448f8b4142acb00efb7e57e575fe6d5aaabec47c.

-> We need to traverse the subtrees to be able to pick up debug and highlight modifiers
Updated tests to account for modifiers inside AbstractPolyNodes
fix broken build on mingw / mxe
Added test for empty geometry
Merge branch 'master' of github.com:openscad/openscad
Remove isinf from mathc99 since we're using boost
Change behavior of intersection: intersecting something with an empty object will be empty
killed warning
killed warning
Added tests for minkowski with only one child