tests: silence output of darcs command

It appears darcs is more verbose by default these days. I got test failure
with Darcs 2.12.4.

tests/test-convert-darcs.t

@@ -1,107 +1,108 b''
 #require darcs
 
   $ echo "[extensions]" >> $HGRCPATH
   $ echo "convert=" >> $HGRCPATH
   $ DARCS_EMAIL='[e-mail]'; export DARCS_EMAIL
 
 initialize darcs repo
 
   $ mkdir darcs-repo
   $ cd darcs-repo
-  $ darcs init
+  $ darcs init -q
   $ echo a > a
   $ darcs record -a -l -m p0
   Finished recording patch 'p0'
   $ cd ..
 
 branch and update
 
   $ darcs get -q darcs-repo darcs-clone >/dev/null
   $ cd darcs-clone
   $ echo c >> a
   $ echo c > c
   $ darcs record -a -l -m p1.1
   Finished recording patch 'p1.1'
   $ cd ..
 
 skip if we can't import elementtree
 
   $ if hg convert darcs-repo darcs-dummy 2>&1 | grep ElementTree > /dev/null; then
   >     echo 'skipped: missing feature: elementtree module'
   >     exit 80
   > fi
 
 update source
 
   $ cd darcs-repo
   $ echo b >> a
   $ echo b > b
   $ darcs record -a -l -m p1.2
   Finished recording patch 'p1.2'
 
   $ darcs pull -q -a --no-set-default ../darcs-clone
   Backing up ./a(*) (glob)
   We have conflicts in the following files:
   ./a
+   (?)
   $ sleep 1
   $ echo e > a
   $ echo f > f
   $ mkdir dir
   $ echo d > dir/d
   $ echo d > dir/d2
   $ darcs record -a -l -m p2
   Finished recording patch 'p2'
 
 test file and directory move
 
-  $ darcs mv f ff
+  $ darcs mv -q f ff
 
 Test remove + move
 
-  $ darcs remove dir/d2
+  $ darcs remove -q dir/d2
   $ rm dir/d2
-  $ darcs mv dir dir2
+  $ darcs mv -q dir dir2
   $ darcs record -a -l -m p3
   Finished recording patch 'p3'
 
 The converter does not currently handle patch conflicts very well.
 When they occur, it reverts *all* changes and moves forward,
 letting the conflict resolving patch fix collisions.
 Unfortunately, non-conflicting changes, like the addition of the
 "c" file in p1.1 patch are reverted too.
 Just to say that manifest not listing "c" here is a bug.
 
   $ cd ..
   $ hg convert darcs-repo darcs-repo-hg
   initializing destination darcs-repo-hg repository
   scanning source...
   sorting...
   converting...
   4 p0
   3 p1.2
   2 p1.1
   1 p2
   0 p3
   $ hg log -R darcs-repo-hg -g --template '{rev} "{desc|firstline}" ({author}) files: {files}\n' "$@"
   4 "p3" ([e-mail]) files: dir/d dir/d2 dir2/d f ff
   3 "p2" ([e-mail]) files: a dir/d dir/d2 f
   2 "p1.1" ([e-mail]) files: 
   1 "p1.2" ([e-mail]) files: a b
   0 "p0" ([e-mail]) files: a
 
   $ hg up -q -R darcs-repo-hg
   $ hg -R darcs-repo-hg manifest --debug
   7225b30cdf38257d5cc7780772c051b6f33e6d6b 644   a
   1e88685f5ddec574a34c70af492f95b6debc8741 644   b
   37406831adc447ec2385014019599dfec953c806 644   dir2/d
   b783a337463792a5c7d548ad85a7d3253c16ba8c 644   ff
 
 #if no-outer-repo
 
 try converting darcs1 repository
 
   $ hg clone -q "$TESTDIR/bundles/darcs1.hg" darcs
   $ hg convert -s darcs darcs/darcs1 2>&1 | grep darcs-1.0
   darcs-1.0 repository format is unsupported, please upgrade
 
 #endif