fncache: remove the rewriting logic The fncache could rewrite itself during a read operation if it noticed any entries that were no longer on disk. This was problematic because it caused Mercurial to perform write operations outside the scope of a lock or transaction, which could interefere with any other pending writes. This will be replaced in a future patch by logic that cleans up the fncache as files are deleted during strips.

pull: prevent duplicated entry in `op.pulledsubset` In the bare pull case we could add the same node multiple time to the `pulloperation.pulledsubset`. Beside being a bit wrong this confused the new revset implementation of `revset._revancestor` into giving bad result. This changeset fix the pull operation part. The fix for the revset itself will come in another changeset.

bundle2: part params