Synchronize with potato-branch again:

Synchronize with potato-branch again:
debian/changelog: update to 1.6.10
scripts/dpkg-divert.pl: reinstate last writeability-patch. Modified
to not abort on ENOENT: this indicates a directory does not (yet)
exist. If this happens don't try to rename.
scripts/update-alternatives.pl:
+ update usage-warning to reflect the new --config option
+ Document some global variables
+ Switch back to auto-mode when removing a manually selected alternative
dselect/{dselect.h,main.cc,pkglist.cc}: remove CAN_RESIZE stuff
dselect/methlist.cc: don't abort if getch fails due to interrupted syscall
dselect/pkglist.cc: don't abort if getch fails due to interrupted syscall
dselect/baselist.cc: put debug-statement in sigwinchhandler and
actually resize the current terminal before redisplaying the screen