Turn Glasbey lookup table into a static class

This avoids hassle with properly exporting GLASBEY_LUT and GLASBEY_LUT_SIZE variables.
Header mising - compilation failed
Merge pull request #1001 from taketwo/update-glasbey-colors

Turn Glasbey lookup table into a static class
Merge pull request #1011 from taketwo/fix-981

Add missing header to `example_lccp_segmentation.cpp`