When checking for drange, check if non-None instead of checking for the existance of the key.
OpH5WriterBigDataset: Support datasets with no channel axis.
OpFilterLabels: Support 32-bit machines.
OrderedSignal.unsubscribe() more efficient by using OrderedDict
optimization: ready() uses generator expression, which short-circuits
Rewrote MetaDict to subclass defaultdict.

This speeds up and simplifies __getattr__ and __setattr__. This
optimization is useful for graphs with many lanes, because meta
information is accessed so often.
tests: Use tmp dir for test npy data.
clarified the meaning of parent and graph in class Operator
fix BIG bug in orderedsignal.py
Added OpDenseLabelArray
Slot: When asserting due to not slot.ready(), attempt to find the unready upstream input slot that is causing the problem.
new take on rewriting missing data interpolation
fixed failing testOpStackWriter

The usage 
```python
a.reshape(*tuple())
```
is afaik not officially supported (see http://docs.scipy.org/doc/numpy/reference/generated/numpy.reshape.html, which is the method that is inherited). The shape should not be expanded with the asterisk.
Merge pull request #90 from burgerdev/patch-1

fixed failing testOpStackWriter
Merge pull request #89 from burgerdev/interpmissingdata2

new take on rewriting missing data interpolation
Slot: Added assert to check destination (a.k.a. result) array dtype matches output slot dtype.
'missing labels' detection speedup and simplification
OpFilterLabels: Avoid an unecessary temporary array.
Added assert: MetaDict.assignFrom() param must be another MetaDict
Merge pull request #91 from burgerdev/pr-speedup-missing

'missing labels' detection speedup and simplification