Genera: better support lambda, add read-sequence, write-sequence.
Bump version to 3.1.2.3
Add 3.1.2 to the versions that upgrades are tested against.
Tweak the debian release script...
Add proper ignorable declaration in with-temporary-file:
when there is an after body using the pathname,
the pathname can but need not be used in the before body.
Update the debian files.
Update the XCVB build files somewhat.
Won't build unless we either tell XCVB about package-inferred-systems,
or add #+xcvb (module ...) declarations to every file in ASDF.
doc tweaks: one more file to clean in doc/;
better comment on how to use one of the contribs.
Delete obsolete .pdf file that probably wasn't meant to be committed.
Bump version to 3.1.2.4