Remove log line from batch agent.
Edge change agent emits unenriched types with enriched.

Up until this point, the Edge Change agent emitted only one edge change event
on Relink and Backlink user actions, though, essentially, Relink and Backlink
events are still Link events. Though this is not a bug, this makes it
difficult to reason about counting link events in other agents such as the
rate limiter agent.

For example say you have a limit on Link events, but not Relink events. This
allow users to abuse actions on the site that result in Relinks, despite the
fact that the user is spamming the same action.

Accordingly, this commit changes the edge change transformer to emit a Link
event with every Relink and Backlink event.
Ensure that strings written to memchaced are ascii encoded.
Improvements to testing with h2 database.

Prior to this commit the h2 database was not truncated between unit tests.
This makes it difficult to reason about unit tests separately since each test
can operate on the same data.

While there are other ways of truncating an h2 database using finalizing
control blocks as in

http://naturalsoftware.blogspot.de/2009/06/hey-scala-finalize-this.html

a simple DROP OBJECTS command has been added here to the sql fixture to keep
things simple. Should more complicated testing patterns be required the
finalization strategy will be added.
Merge pull request #6 from soundcloud/network-updates

Transformer, Memcached, and testing updates.