updated sdist path
starting to uncouple the gui subpackage

- task.py really needs to stop depending on the nsdocument’s behavior…
finally able to get rid of the initialize() nonsense

- no longer any use for the script.py appendage either
simplified namespace init

- export function/classes now properly contextualized
variable names & cache invalidation
color() subsumed colormode() and colorrange()

- when called with just kwargs (or just a positional mode arg), updates
the context’s state.
- if component values are supplied, mode & range args apply for that
invocation alone.
better comments
[['added'], 'nested', ('list', 'flattener')]
pen, fill, stroke, and color are now context managers

- also added plotstyle() which resets all the draw-state variables at
the end of the block (and accepts fill/stroke/pen/color mgrs as
positional args)