Drop the use of indirect blocks for storing pointers to data.

Drop the use of indirect blocks for storing pointers to data.

Now store the entire list of blocks that contain each file's contents
inline in the metadata log, even when that list is large.  Previously, the
list was split out into a separate object when it contained more than 8
entries.  These indirect blocks may still be useful, but they also
complicate the metadata/statcache rewrite, so for the moment disable them.
They may be reintroduced later.