- stop erroring on utf-8 output
  - use the right syntax for redirecting stderr
  - don't display sections with no output
  - indicate vimwiki path

Shells out twice in a silly way.

Adds a --file option that will either:

  - pull the date from a vimwiki filename
  - pull the date from a p1k3 entry path
  - pull the day from file's mtime

Aggregates some stuff by date range.