Wish: Add "SplitCreasedSurfaces" optional argument to AddBrep()

[dalefugier]

When adding a Brep to the document, it would be great to tell Rhino's automatic kink splitter not to split kinky faces.

[sbaer]

Added in commit https://github.com/mcneel/rhinocommon/commit/fd9daa5eb3755dd566662af425772b7483941e49