fixed problem with older pickled detectors, and a real bug with
roi.py: Fixed doctests, minor cleanups.
OpBlockedSparseLabelArray: Don't set the entire image dirty when a label is deleted.  Mark each block with a separate dirty notification.
OpFeatureMatrixCache: Blocks with no labels are not dirty once they've been read.
tests: Fixed typo in assertion message.
OpCompressedCache: Ensure that chunkshape is always smaller than the blockshape, even for edge blocks (which are smaller than the other blocks).
Added OpCompressedUserLabelArray as a drop-in replacement for OpBlockedSparseLabelArray (except for some outputs) and test (based on a modified version of the OpBlockedSparseLabelArray test)
OpFeatureMatrixCache: If there are no labels and therefore no features, return a 0-length matrix with the correct number of columns.
Merge branch 'compressed-user-labels'
OpDenseLabelArray: Allow MetaInput to have multiple channels, and force output shape to have 1 channel.
tests: Dvid tests fixed to actually run on windows instead of just skipping them.
submodules: Updated dvidclient
BlockwiseFileset: Automatically increase open file limit when the first blockwise fileset is created.
(Now we can actually run the blockwise fileset tests on mac.)
OpCompressedCache: Don't close all cache files every time setupOutputs() is called.
(If the data can't be regenerated, e.g. in a labeling operator, then closing the cache files discards the data.)
OpCompressedCache: Minor refactoring to make it easier for subclasses to use specific member functions.
Also, added a special fast-path to be used by the label array subclass when writing an all-zero block.
OpCompressedUserLabelArray: Refactored as a subclass of OpCompressedCache:
- Now explicitly aware that any data NOT in the cache is automatically zeros.
- Does not create new cache blocks during execute() ONLY during setInSlot().
Merge branch 'compressed-labels-rewrite'
submodules: Updated dvidclient.
Slot: setValue() checks shape of arrays before checking equality.
fixes #128