For the purpose of breaking a filepair, diffcore-break examines
the extent of changes between the contents of the files before
and after modification (i.e. the contents that have "bcd1234..."
-and "0123456..." as their SHA1 content ID, in the above
+and "0123456..." as their SHA-1 content ID, in the above
example). The amount of deletion of original contents and
insertion of new material are added together, and if it exceeds
the "break score", the filepair is broken into two. The break