Issue #426: Seam allowance. Special cases for dart. (dismine/valentina)

New issue 426: Seam allowance. Special cases for dart. https://bitbucket.org/valentinateam/valentina/issues/426/seam-allowance-special-cases-for-dart

Roman Telezhinskyi:

I have found two special cases of seam allowance when we deal with darts.

  1. Ignore seam allowance. Image dart1.png.
  2. Special seam allowance. Image dart2.png.