Python 3 support

• Python 3 support added
• Fixed hard-coded path to views
• Fixed missing numexpr for tests

Keep views sorted

Merge pull request #10 from manahl/keep_view_order

Keep the view order consistent with registration and prepare for release

Robust view loading

When a single view fails to load, do not stop the rest from loading.

UI improvements

• Index page with a list of registered views
• safe HTML in cells
• regex based replacement formatter
• fixes for Pandas compatibility issues in sort and histogram transformers

List / filter views

• View list / filter endpoint
• Fixes for Mongo session storage and PDF viewer

Initial release

Merge pull request #1 from manahl/pep8_reformat

Reformatted code