Namespace collision between class UF and class UF

[AustinSchuh]

Both cuda/src/labeling_oliveira_2010.cu and include/labels_solver.h define class UF in the global namespace. I'm seeing a crash where cuda/src/labeling_oliveira_2010.cu's Alloc appears to call include/labels_solver.h. Renaming Alloc inside cuda/src/labeling_oliveira_2010.cu fixes it. It is probably best to rename UF inside cuda/src/labeling_oliveira_2010.cu.