OR connection early-flush code in connection_handle_write_impl is needless
Long ago, before we had cell queues, it was necessary to maybe call connection_handle_write() from connectino_write_to_buf_impl() on OR connections, so that we wouldn't get into a loop of reading infinite amounts of data and queueing it all on an outbuf before bothering to write any data.
If that doesn't sounds like what our code does now, you're right: right now, we won't stick more than OR_CONN_HIGHWATER bytes of cells on an outbuf, and we won't suck more than CELL_QUEUE_HIGHWATER_SIZE cells off any edge connection. So, there's no more call for that code.
Removing this code will simplify our code flow, and that should be something we can all get behind.
Discovered by a user on IRC. Marking this for 0.2.4, though we can backport to 0.2.3 if it turns out to be safe. If we're not 100% sure here, we could simulate before merging.