manifest: remove dependency on manifestrevlog being able to create trees...
manifest: remove dependency on manifestrevlog being able to create trees
A future patch will be removing the read() function from the manifest class.
Since manifestrevlog currently depends on the read function that manifest
implements (as a derived class), we need to break the dependency from
manifestrevlog to read(). We do this by adding an argument to
manifestrevlog.write() which provides it with the ability to read a manifest.
This is good in general because it further separates revlog as the storage
format from the actual inmemory data structure implementation.
