Svviz

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fixed a regression that prevented the demo from being run from python2

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minor tweaks

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Adds support for python 3.x (python 2.7 will continue to be supported as well).

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Bugfixes:

- fixed an error with running demos

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Improvements:

- added an option ``--export-insert-sizes`` which exports the insert size distribution plots to png files, one per event per sample.
- added better warning and error messages around command line arguments
- output progress every 30 seconds when not in an interactive shell (eg stderr redirected to file)
- demo data is now downloaded from github

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Improvements:

- now supports ``<TRA>``-style translocations
- added a new ``--sample-reads`` option that can be used to downsample reads (read pairs) -- use with caution!

Bugfixes:

- removed joblib dependency (joblib 0.10 introduced some API changes that were not compatible with svviz)