svn merge -r 9476:9506 https://svn.cs.uu.nl:12443/repos/trace/nix/trunk

#already done:
# 8628 
# 8632
# 8634
# 8636
# 8655
# 8691
# 8698
# 8711
# 8864
# 9063
# 9105 
# 9207
# 9217
# 9332
# 9429
# 9433
# 9435
# 9437
# 9439
# 9445
# 9476
# 9506