#9 RebuilderStream improper check against oldFile length

[Kostis Anagnostopoulos]

At RebuilderStream:194 the following precaution-check against old-file's length is invalid:
int len = Math.min(delta.getBlockLength(),
(int) (basisFile.length() - ((Offsets) delta).getOldOffset()));

Indeed, the rebuilding SHOULD fail if
( delta.getBlockLength() + delta.getOldOffset() )
falls outside old-file, in order to detect bad reconstruction process
(either due to agorithm bugs or if old-file changes since sigs-generation)

Reported against svn-trunk, rev: 193