Sinatra not found improperly logged

Now Sinatra 404's are not submitted to NewRelic, just like Rails' routing errors.
Add a test and another default for the patch from Moreno Carullo

- Multiverse test
- Ignore Sinatra::NotFound in
  NewRelic::Agent::Configuration::DEFAULTS too.
Revert changes accidentally committed to release
RUBY-1063 Be less alarmist about EOFErrors talking to collector

Three things:
1. Don't retry immediately for EOFErrors when talking to the
   collector, just wait for the next harvest cycle.
2. Bump the main log level for this specific error down to warn.
3. Log the backtrace at debug to avoid flooding logs (esp. for
   customers on Heroku)
Don't arbitrarily suppress warning if timeout posting to collector is <30s

See discussion in https://github.com/newrelic/rpm/pull/69
Pin release Resque tests to 1.23.0 (upstream changes on dev will make this unnecessary)
Remove test which is made obsolete by Resque 1.23.1

This test asserts that the agent logs a problem when someone overrides
the Resque.before_fork hook we rely on.  Resque 1.23.1 fixes this
problem by adding chainable hooks, and therefore the test fails.  The
log logic is tested elsewhere so this test seems safe to remove.

Conflicts:
	test/multiverse/suites/resque/Envfile
Clean up Resque instrumentation tests a bit:

* Run tests with 1.23.0 and ~>1.24.1 (to make sure we're covering
  both old and new hook behavior, and avoid a bug in 1.23.1 - 1.24.0
  where worker.rb relied on Time#iso8601 but didn't explicitly require
  'time')
* Set TERM_CHILD when starting Resque to squelch a warning