Code review comment for lp:~pbeaman/akiban-persistit/fix_1018526_temp_trees_in_journal

A static final end for the two magic values (12345 and _temporary_volume) would be nice. Coming across that in the future could be confusing otherwise.

Now that tree handles are always loaded proactively, it might be nice to make JournalManage#handleForTree() private/package, grab the current handle in usages in Transaction, and assert in the various JournalManager#write* methods that the incoming handling is non-0.

I don't mean to harp, but since we are trying to fix a bug about the handle lifetime it seems preferable to check all of our assumptions related to it.