revbranchcache: write cache even during read operations...
revbranchcache: write cache even during read operations
Previously we would only actually write the revbranchcache to disk if we were in
the middle of a write operation (like commit). Now we will also write it during
any read operation. The cache knows how to invalidate itself, so it shouldn't
become corrupt if multiple writers try at once (and the write-on-read
behavior/risk is the same as all our other caches).