Merge remote-tracking branch 'mvo/feature/helpful-apt-list' into debian/sid

Conflicts:
	test/integration/test-apt-cli-list

diff --cc test/integration/test-apt-cli-list
index 6fc4bc7,b738bcc..40bf81a
--- 1/test/integration/test-apt-cli-list
--- 2/test/integration/test-apt-cli-list
+++ b/test/integration/test-apt-cli-list
@@@ -51,8 -58,8 +58,14 @@@ bar/now 1.0 i386 [installed,local
    an autogenerated dummy bar=1.0/installed
  " apt list bar --verbose
  
 +# test for dpkg ^rc state
 +insertinstalledpackage 'conf-only' 'i386' '1.0' '' '' 'deinstall ok config-files'
 +testequal "Listing...
 +conf-only/now 1.0 i386 [residual-config]" apt list conf-only
 +
+ # ensure that the users learns about multiple versions too
+ testequal "Listing...
+ baz/unstable 2.0 all [upgradable from: 0.1]
+ N: There are 2 additional versions. Please use the '-a' switch to see them." apt list baz -o quiet=0
+ 
++