[asdf-devel] Please test 2.20.16

[Faré]

OK, so I propose we freeze the current state of ASDF for a release 2.21,
hopefully some time next week.
Please test 2.20.16.

Changes since 2.20:
* New features:
 * Most importantly, encodings.
  ASDF now lets you specify an :encoding for a system, module or component,
  that is used when loading or compiling Lisp files.
  See the documentation.
  By default, the only useful value is :utf-8, and
  we recommend you use UTF-8 everywhere.
  We intend to make it the default in the future
  (current default is the legacy behavior of using whichever implicit
  default your underlying implementation is currently configured to use).
  An extension asdf-encodings is available that supports more encodings,
  including autodetection of encoding in the near future.
 * You can now specify :hostname in your asdf-output-translations,
  so you can easily share a home directory yet split its fasl cache
  between several subtly different machines.
* Bug Fixes:
 * lp#982285. since 2.014.4, the default source-registry
  was skipping anything from /usr or XDG_DATA_DIRS,
  because of a missing test in getenv-absolute-pathnames. Fixed in .15.
 * In 2.019.9 aka 2.20, ECL support was broken by using
  a function in the wrong package (defined in cl-user). Fixed in .1.
 * logical-pathname support was somewhat broken since 2.017.6,
  due to the way most implementations fail to read physical namestrings
  when *default-pathname-defaults* is a logical-pathname.
  Fixed, together with other logical-pathname issues,
  and a test case was added to the test suite to ensure no further regression.
  Works great modulo quirks around implementation bugs on CLISP and Allegro.
* Minor tweaks:
 * Use :unspecific in pathname components on more implementations.
 * export and/or document more utilities.
 * add a few missing compatfmt for Genera.

I do not intend to make any further changes to ASDF before the 2.21 release,
except for fixes to any bug found, of course.
Experiments with encodings and autodetection are redirected to
the asdf-encodings system for the time being.
Discussion of a possible merge of asdf-encodings into ASDF
will happen only after asdf-encodings itself is reasonably stable.

—♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org
The mice which helplessly find themselves between the cats teeth acquire no
merit from their enforced sacrifice.		— Mahatma Gandhi