mq: truncate patch just before rewriting header

convert: raise Abort instead of NoRepo when CVS pserver auth fails. At this point we know the source is CVS, so we should not go through the rest of the converters.

convert: hg: optionally create branches as clones If convert.hg.clonebranches is set, branches will be created as clones of their parent revisions. All clones will be subdirectories of the destination path.