Upsetplot

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- Fixed a regresion which caused the first column to be hidden
(:issue:`125`)

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- Fixed issue with the order of catplots being reversed for vertical plots
(:issue:`122` with thanks to :user:`Enrique Fernandez-Blanco <ennanco>`)
- Fixed issue with the x limits of vertical plots (:issue:`121`).

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- Fixed large x-axis plot margins with high number of unique intersections
(:issue:`106` with thanks to :user:`Yidi Huang <huangy6>`)

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- Fixed the calculation of percentage which was broken in 0.4.0. (:issue:`101`)

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- Added option to display both the absolute frequency and the percentage of
the total for each intersection and category. (:issue:`89` with thanks to
:user:`Carlos Melus <maziello>` and :user:`Aaron Rosenfeld <arosenfeld>`)
- Improved efficiency where there are many categories, but valid combinations
are sparse, if `sort_by='degree'`. (:issue:`82`)
- Permit truthy (not necessarily bool) values in index.
(:issue:`74` with thanks to :user:`ZaxR`)
- `intersection_plot_elements` can now be set to 0 to hide the intersection
size plot when `add_catplot` is used. (:issue:`80`)

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- Added `from_contents` to provide an alternative, intuitive way of specifying
category membership of elements.
- To improve code legibility and intuitiveness, `sum_over=False` was deprecated
and a `subset_size` parameter was added. It will have better default
handling of DataFrames after a short deprecation period.
- `generate_data` has been replaced with `generate_counts` and
`generate_samples`.
- Fixed the display of the "intersection size" label on plots, which had been
missing.
- Trying to improve nomenclature, upsetplot now avoids "set" to refer to the
top-level sets, which are now to be known as "categories". This matches the
intuition that categories are named, logical groupings, as opposed to
"subsets". To this end:

- `generate_counts` (formerly `generate_data`) now names its categories
"cat1", "cat2" etc. rather than "set1", "set2", etc.
- the `sort_sets_by` parameter has been renamed to `sort_categories_by` and
will be removed in version 0.4.