ghc-pkg prints warnings to stdout instead of stderr

[nomeata]

The warning

WARNING: cache is out of date: /var/lib/ghc-6.12.1/package.conf.d/package.cache
  use 'ghc-pkg recache' to fix.

is printed to stdout, which breaks scripts. It should be printed to stderr instead.

[igloo]

There is quite a mix of stderr/stdout. This really needs a policy to be decided, and a sweep over all the prints to be done.

[p.capriotti@…]

commit d6b1050d7e5db5a196a50bf3ad34ce310cb2387e

Author: Paolo Capriotti <p.capriotti@gmail.com>
Date:   Wed Mar 7 18:40:44 2012 +0000

    ghc-pkg: make sure info messages go to stdout and errors to stderr (#3818)

 utils/ghc-pkg/Main.hs |   70 ++++++++++++++++++++++++++++---------------------
 1 files changed, 40 insertions(+), 30 deletions(-)