Fix lids imports

sortof

boxes/__init__.py

@@ -635,6 +635,7 @@ class Boxes:
         self.hexHolesSettings = HexHolesSettings(self.thickness, True,
                 **self.edgesettings.get("HexHoles", {}))
         # Lids
+        from . import lids
         self.lidSettings = lids.LidSettings(self.thickness, True,
                                        **self.edgesettings.get("Lid", {}))
         self.lid = lids.Lid(self, self.lidSettings)

boxes/lids.py

@@ -14,6 +14,7 @@
 #   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from boxes import edges, Boxes
+import math
 
 class LidSettings(edges.Settings):