Katdal

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* Python 3 support via python-future (finally!)
* Load L1 flags if available (164)
* Reduced memory usage (165) and speedups (155, 169, 170, 171, 182)
* S3 chunk store now uses requests directly instead of via botocore (166)
* Let lazy indexer use oindex semantics like in the past (180)
* Fix concatenated data sets (161)
* Fix IPython / Jupyter tab completion for sensor cache (176)

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* Restore NumPy 1.14 support (all data flagged otherwise)

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* Rally around the MeerKAT Visibility Format (MVF)
* First optimised converter from MVF v4 to MS: mvftoms
* Latest v4 fixes (synthetic timestamps, autodetection, NPY files in Ceph)
* Flag and zero missing chunks
* Now requires katsdptelstate (released), dask, h5py 2.3 and Python 2.7
* Restore S3 unit tests and NumPy 1.11 (on Ubuntu 16.04) support

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* New HDF5 v3.9 file format in anticipation of v4 (affects obs_params)
* Fix receiver serial numbers in recent MeerKAT data sets
* Add dask support to ChunkStore
* katdal.open() works on v4 RDB files

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* New ChunkStore and telstate-based parser for future v4 format
* Use python-casacore (>=2.2.1) to create Measurement Sets instead of blank.ms
* Read new-style noise diode sensor names, serial numbers and L0 stream metadata
* Select multiple polarisations (useful for cross-pol)
* Relax the "expected number of dumps" check to avoid spurious warnings
* Fix NumPy 1.14 warnings

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* Fix upside-down MeerKAT images
* SensorData rework to load gain solutions and access telstate efficiently
* Improve mapping of sensor events onto dumps, especially for long (8 s) dumps
* Fix NumPy 1.13 warnings and errors
* Support UHF receivers