My first attempt at refolding natural constants led to all names
being printed with their namespace prefixes. This fixes that,
most notably by introducing the massive `mapPTermM` function in
`Idris.Syntax`.
This is the result of running the command:
$ find . -name '*.idr' -type f -exec sed -i -E 's/\s+$//' {} +
I confirmed before running it that this would not affect any markdown
formatting in documentation comments.
