Fixed v-carve depth calculation in the presence of a bottom diameter, added unit tests and cleaned up the v-bit parameter naming.

src/Mod/Path/TestPathApp.py

@@ -42,6 +42,7 @@ from PathTests.TestPathDeburr  import TestPathDeburr
 from PathTests.TestPathHelix  import TestPathHelix
 from PathTests.TestPathVoronoi  import TestPathVoronoi
 from PathTests.TestPathThreadMilling  import TestPathThreadMilling
+from PathTests.TestPathVcarve  import TestPathVcarve
 
 # dummy usage to get flake8 and lgtm quiet
 False if TestApp.__name__ else True
@@ -64,4 +65,5 @@ False if TestPathPreferences.__name__ else True
 False if TestPathToolBit.__name__ else True
 False if TestPathVoronoi.__name__ else True
 False if TestPathThreadMilling.__name__ else True
+False if TestPathVcarve.__name__ else True