LJ::delete_entry — Deletes a user's journal entry
LJ::delete_entry(uuserid, jitemid, quick, anum);
uuserid. Journal itemid or $u object of journal to delete entry from
jitemid. Journal itemid of item to delete.
anum. The log item's anum, which'll be needed to delete lazily some data in tables which includes the anum, but the log row will already be gone so we'll need to store it for later.
boolean; 1 on success, 0 on failure.