debug: copy tracer additions onto debug tracer
docs: add warning to trace_tracer docs
connection: retry logic works again

Sometime back in January, I think, I broke the logic that caused the
agent to repeatedly try to connect to New Relic (with backoffs between
attempts). This stuff is pretty tricky to test in situ, which is why the
new test case involves time travel (a feature I didn't know Sinon
supported).
docs: log message tweak
api: module users can feed errors into the tracer

Also did some light documentation refactoring to acknowledge that the
API is no longer solely used for transaction naming.
code: ignored transactions are ignored everywhere

Consolidated the old method calls down into one and everything got a lot
easier to reason about. In retrospect this was obvious. Added a bunch
more tests around this as well.
docs: updated for new version
release: published 1.1.0