repoview: make propertycache.setcache compatible with repoview Propertycache used standard attribute assignment. In the repoview case, this assignment was forwarded to the unfiltered repo. This result in: (1) unfiltered repo got a potentially wrong cache value, (2) repoview never reused the cached value. This patch replaces the standard attribute assignment by an assignment to `objc.__dict__` which will bypass the `repoview.__setattr__`. This will not affects other `propertycache` users and it is actually closer to the semantic we need. The interaction of `propertycache` and `repoview` are now tested in a python test file.

Issue351: mq: qrefresh can create extra revlog entry

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init
  $ hg qinit

  $ echo b > b
  $ hg ci -A -m foo
  adding b

  $ echo cc > b
  $ hg qnew -f foo.diff
  $ echo b > b
  $ hg qrefresh

  $ hg debugindex b
     rev    offset  length  ..... linkrev nodeid       p1           p2 (re)
       0         0       3  .....       0 1e88685f5dde 000000000000 000000000000 (re)