retry couch requests once

Couch sometimes responds with 500 or so. Often this is temporary. Let's retry once and log the error instead of dying.
ensure we log all errors
better debug loggin, sleep before retrying
Version 0.3.2 - staying alive

This version mainly improves the stability and should keep tapicero from dying too early.

* couchrest_changes 0.0.5 will resume if the connection died.
* lock yajl version to 1.1.0 - 1.2.0 requires mkmf on the server
* retry couch requests in case they fail
* log all crashes