add ojph-encode-kdu-decode path

[michaeldsmith]

There are currently 2 paths:

1. kdu-encode kdu-decode

exrkdu --ipath input.exr --epath output.exr

2. kdu-encode ojph-decode

exrkdu --ipath input.exr --epath output.exr -d

The success of Path 1 and Path 2 demonstrate that a files encoded with Kakadu can be decoded with either Kakadu or OpenJPH with the same result

A 3rd path could be added to demonstrate that files encoded with OpenJPH can be decoded with Kakadu with the same result

3. ojph-encode kdu-decode

maybe using the -e (default encoder) option?

a 4th path would complete the testing options, allowing the tool to use OpenJPH for both encoding and decoding

4. ojph-encode ojph-decode

using the -d option and whatever option is selected for 3) (-e ?)