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.
'a' in d: True
d['a']: va
'b' in d: True
d['b']: vb
'c' in d: True
d['c']: vc
'd' in d: True
d['d']: vd
'a' in d: False
'b' in d: True
d['b']: vb
'c' in d: True
d['c']: vc
'd' in d: True
d['d']: vd
'e' in d: True
d['e']: ve
'b' in d: True
d['b']: vb2
'c' in d: True
d['c']: vc2
'd' in d: True
d['d']: vd
'e' in d: False
'f' in d: True
d['f']: vf