3rd_party/glu-tess: prevent merging with excluded faces
3rd_party/glu-tess: prevent merging with excluded faces

When emitting boundaries, prevent the merging with those
GLUface objects that contain an out-boundary point (this
is marked by that the client ID has value
FASTUIDRAW_GLU_nullptr_CLIENT_ID).

01org/fastuidraw,01org/fastuidraw