Implement AppMetrics log parsing

Originally referenced in #5, we need to support [AppMetrics logs](https://github.com/fandrei/AppMetrics/blob/master/samples/ReportingToAppMetrics/Program.cs#L49). It seems like the format is very simple.

    2012-04-02 08:56:16.0527220\tLatency TestMethod\t0.0992977

It sounds like the log format can be changed if need be, but I'd recommend sticking to simple formats for internal logging and avoid the overhead of a "cloud-friendly" JSON format - particularly if they generate lots of noise.