Diffviewer/processors.py determined if a chunk was valid by checking it against the orig (left) range.  This was causing some deletes in interdiffs to be marked as filtered-equal when the diff showed up in the interfilediff and not the filediff.

- Changed processors.py to validate a chunk by checking it against the orig and new (left and right) ranges since deletes won't always show up on the left side.

- Corrected the expected new_opcodes in diffviewer/tests/test_processors.py FilterInterdiffObcodesTests to expect a 'delete' instead of 'filtered-equal' for the delete opcode.

Corrected the expected new_opcodes in diffviewer/tests/test_processors.py FilterInterdiffObcodesTests to expect a 'delete' instead of 'filtered-equal' for the delete opcode.
All tests pass.