- change adaptive refinement in FarMeshFactory to not refine inside holes,
  while retaining a necessary 1-ring on the inside of a hole edge

- add IsInsideHole() function to HbrHalfEdge

- add HasChild() function to HbrVertex and HbrHalfedge

- add a regression shape with adjacent holes and creases (tests dart, crease & boundaries)

Note : this does not address hierarchical edits inside holes or hole tags in hierarchical edits

fixes #78
Merge branch 'master' of github.com:PixarAnimationStudios/OpenSubdiv