0025945: Make stable checking of shape global properties in tests

- Added function checkprops, set default tolerance parameter to 1.0e-4
- Using "area" instead of "square".
- Options "-equal\notequal" isn't used together with "-s" in blend and offset test cases.
- Correct regressions/differences/improvements and CPU problem (set props tolerance to 0.1)
- Corrected test cases to use checkprops proc.
- Correct image difference
- Updated TODOs in test cases.
- Updated test cases to get correct images of result shape

tests/bugs/moddata_2/bug266

@@ -18,6 +18,6 @@ explode face f
 chamf result face edge_10 face_3 A 1 45 edge_6 face_3 A 1 45 edge_11 face_3 A 1 45 edge_12 face_3 A 1 45 edge_13 face_3 A 1 45 edge_14 face_3 A 1 45 edge_8 face_3 A 1 45 edge_9 face_3 A 1 45
 checkshape result
 
-set square 48913
+checkprops result -s 48913
 set 2dviewer 0