Revert "remove d7 image style config from d6 version"

This reverts commit 21890f120005c6562720503c41f324b75a7c27f9.
Revert "remove d6 imagecache config from d7 version"

This reverts commit 9e434a7453dd1eafe007c0d6724d28543cf68617.
comment out d6 imagecache rules in d7 config & vice-versa and add brief explanation in comments