The changelog operation type is unsigned. Also, no need to convert the type to a string to see if it's valid; use CL_LAST for that.
tests/lustre_fs/report.out is a generated file. Remove it.
(WIP) Re-organize the changelog reader to process the renames diffently.
If a CL_EXT is expected, temporarily store the CL_RENAME record.

The code is still doing UNLINK/RENAME/EXT, but eventually RENAME and EXT will be collapsed.

This fixes test 108b.