add pixel-level difference for visitBorder
Merge remote-tracking branch 'upstream/master' into blockwise-watersheds

Conflicts:
	test/CMakeLists.txt
Merge branch 'view-blockwise-labeling' into blockwise-watersheds
Merge branch 'view-blockwise-labeling' into blockwise-watersheds
prepareWatersheds
add optional diff argument for labeling
small working example for blockwise watershed
add overlap generator for chunked arrays (untested)
Merge branch 'view-blockwise-labeling' into blockwise-watersheds
add chunked array support for blockwise watershed
refactor: move both blockwise algorithms in a single directory
remove swap file
fix visit border pixel diff problem
make normal union find watershed equivalent to blockwise algorithm
add default for parameter, fix wrong function name
add proper tests for blockwise watershed
add missing #define for bounds checking
change plateau id value
add FIXME
refactor and generalize generator for overlapping block views