Created error monitor for use by instrumentation.
Added context to assertions.
Make sure that error counts are correct for web.

When Node supports background tasks, will need to split error counts
across transactions.

Also removed TODO that is, I beileve, handled.
Add error tracing to fs.
Reduce copying by binding instead.
Trace errors for http.createServer and http.request.
Merge branch 'master' into errors

Pulling in newest shutdown command support.
Faster, caster!
When we need direct stream instrumentation, we'll actually add it.
Only try to shut down if we're connected.
Rewrote Express instrumentation to consolidate code.

Also added error trapping to Express 2 and 3.
Improve documentation.
Send stacktraces for errors when available.
Formatting.
Merge branch 'master' into errors

Pull in changes related to most recent release.
Instrumented functions now use more comprehensible names.
Minor documentation clarification.
Be very careful about using external dependencies in instrumentation.
Two years pass in the blink of an eye.
Merge branch 'master' into errors