RUBY-1083 DataMapper instrumentation uses ActiveRecordHelper in determining rollup metrics
RUBY-1083 omit top-level DB rollup outside of web transactions

The ActiveRecord/all metric is used to drive the database portion of
the main overview graph, which is otherwise scoped to web transactions
only. When we record this metric from non-web transactions, we end up
polluting this main overview graph. This change avoids that pollution.

Operation-specific rollup metrics (e.g. ActiveRecord/find, etc) are
still recorded from non-web transactions, since these don't affect the
main overview graph.
RUBY-1096: Checkpoint of initial work on the request sampler
Add a top-level API for registering for and sending events
Hook up request sampler to method_tracer via :metrics_recorded event
Add a test helper for temporarily outputting debug log to stderr
RUBY-1096 Add the rest of the initial RequestSampler
RUBY-1083 Add some DataMapper tests covering basic metric recording
RUBY-1083 Don't require rake from test_helper, to make it easier to use from multiverse
RUBY-1101 Include frozen txn name in rename warning
RUBY-1067 be more cautious loading ActiveRecord instrumentation
Make RequestSampler re-entrant, incorporate protocol changes:

* Synchronize the sample API
* Prepend the agent_run ID to the post to the Collector
* Include the timestamp of the event in the sample
* Change strings in the sample to use constants to combat object-churn
* Modify the FakeCollector to reflect changes in the Collector
Call #throttle instead of #downsample_data to throttle the sampler
Fix metric name -> ID translation
Add TextMate properties file to the ignorelist
Add tests for throttling
RUBY-1083 Use in_transaction for DataMapper tests, assert ActiveRecord/all omitted
RUBY-1096 NewRelic::Agent.notify wasn't pass params right
RUBY-1083 Use in_transaction helper from Sequel tests
Merge pull request #49 from newrelic/RUBY-1083

Stop polluting DB overview metrics with background tasks