slot: Commented out clean-up calls to disconnect(), since they hide the original exception, despite my best efforts to avoid this.
Seriously, I am out of ideas here.  I think the Python interpreter is to blame.
Python 3 should fix this problem since it supports explicit exception chaining...
OpMultiArrayStacker: If a new axis is inserted into the output, also insert an entry in meta.ideal_blockshape
OpExportSlot: Better error message for IOError during hdf5 export.
OpReorderAxes: Added an assert
blocked array caches: removed an unused meta field (blockshape)