hgview #50379 improve mq support and refresh [validation pending]

Right now, hgview crashes on "hg strip", and yields an empty commit list on "hg qrefresh" or "hg qpop". Besides, it captures repository modifications 'too early' so that we have systematicly to click the refresh button. (I suppose the two problems are related).

appeared in<not specified>
done in1.6.0
load left0.000
closed by<not specified>