mq: print "'foo' 'bar'", not "['foo', 'bar']" when showing guards
The internal list representation of guards was leaking into the
output. The guards were always printed using repr(guard) and that
style was kept.
When "hg qguard -l" prints several guards for a patch, it does so by
joining the names with " " and that style was used for the error
messages too.
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present