setup 2.921 release candidate - please test

setup 2.921 release candidate - please test

[Jon Turney]

A new setup release candidate is available at:

  https://cygwin.com/setup/setup-2.921.x86_64.exe (64 bit version)
  https://cygwin.com/setup/setup-2.921.x86.exe    (32 bit version)

Please test, and report any problems here.

This is not the place for setup feature requests.


Changes compared to 2.919:

- Add perpetual support for preremove scripts (thanks to Christian Franke)

- Major update to libsolv (from 0.6.29 to 0.7.22).  Fix a crash this causes.

- Allow packages to be marked as 'self-destruct'

- Add new option --no-write-registry, which inhibits recording the 
installation root directory in the registry, which may be useful for 
portable or temporary installs (thanks to Christian Franke)

- Various fixes around "All Users/"Just For Me" (thanks to Christian 
Franke for investigating these problems)

-- Fix a long-standing bug (since 2012), where installed files are owned 
by the user's primary group, rather than the Adminstrators group, when 
installing for "All Users".
-- We no longer change group back to the user's primary group while 
running postinstall scripts, when installing for "All Users". This was 
only for the benefit of mkgroup/mkpasswd being run by the postinstall 
script, which we don't do any more.
-- Fix "Just For Me" being ignored, when run with Admininstrator privileges
-- Fix "All Users" being selectable but basically ineffectual, when not 
run with Admininstrator privileges

- Add view modes "Removable" and "Unneeded" (thanks to Christian Franke)

- Add Ctrl-I/R/U as keyboard accelerators for 
install/reinstall/uninstall in the package chooser (thanks to Christian 
Franke)


For instructions on obtaining and building the source code for setup, 
see https://sourceware.org/cygwin-apps/setup.html

Please send bug reports, as usual, to the public mailing list cygwin AT 
cygwin DOT com.