bdiff: tweaks for large files - adjust the common line threshold to .1% this speeds up a delta of 7M lines of source from 10m to 40s - adjust the scaling of the hash array down a bit as it was raising the peak memory usage significantly

adding da/foo
adding foo
% manifest
200 Script output follows


drwxr-xr-x da
-rw-r--r-- 4 foo


200 Script output follows


-rw-r--r-- 4 foo