- Interface is more or less like multidelta.
- Keep in mind it won't work very well; delta is O(N^2) frequently in
practice. multidelta manages to work because it folds lines to keep
N small, but this is just working on raw tokens. However, I have a
fancy pants DAG based delta algorithm which will be the bees knees
once I get it wired to clang.
llvm-svn: 65377
