Remixware v0.2.1

Running Remixware on real projects for the case studies on remixware.com
found code credited in ways it didn't read. These are fixed:

• A licence file kept with the code now counts as credit, as projects that
  vendor a library keep it: typer keeps Click's licence in
  typer/_click/LICENSE.txt, pip keeps each vendored library's in its
  folder, and coyim keeps xmpp-client's in LICENSE.xmpp-client at its
  top. Remixware reads the licence and notice files anywhere in the project,
  outside the folders a scan skips such as vendor/ and node_modules/,
  and a full copyright line or a name in one of them credits the copy, as
  in a notices file. 0.2.0 read only notice files in the top folder and
  the copied file's own header, and called these copies
  attribution-missing. Paths --exclude and the policy's ignore name
  are left out, and source files named like notices (attribution.go)
  and build files named like them (ThirdParty.cmake) aren't read as
  notices, at the top either. Findings that are credited
  carry "credited": true in the JSON report, and notice writes no
  entry for them.
• For a source whose licence text names no copyright holder (the Apache and
  Mozilla texts don't), its own licence text kept whole counts as credit in
  the nearest folder with a licence file (LICENSE, COPYING), starting with
  the copy's own and short of the project's top. If the
  source ships a NOTICE, its NOTICE text has to be there too, and the
  finding says so when only the licence is.
• A short licence file that offers others as a choice ("either of the
  licenses found in LICENSE.APACHE or LICENSE.BSD", as packaging's does) is
  read as that choice, no longer as an unrecognised licence. The files have
  to be listed as alternatives in a sentence that offers the choice; other
  short files that name licence files are read as before.
• Archives and images whose names start like a licence file
  (license.dist-0.1-py2.py3-none-any.whl) aren't read as licence files.
• A source release built with setuptools keeps its licence file at the top
  and its metadata in an .egg-info folder. The package indexed from that
  metadata now takes the release's licence text, copyright lines and
  NOTICE. An index no longer passes a licence or its texts across a
  _vendor or vendored folder, and a project reached through a symbolic
  link is read like any other with --from alone too.
• A licence given in words in pyproject.toml ("ISC License") is read as
  its SPDX id, and words Remixware can't place no longer become a licence
  of their own.
• scripts/case_studies.py records the case studies (typer and Click,
  coyim and xmpp-client, pip's vendored libraries) in
  test/results/case-studies.