Maven integration

[Julien Nicoulaud]

Hi,

First of all thanks for this great tool, this is a real game changer.

For those interested, here is a sample pom.xml running JMH benchmarks as
part of the build: https://gist.github.com/nicoulaj/5517176

I started working on a Maven plugin for JMH, but a few things complicate
JMH embedding:

   - Arguments parsing: it would be great if there was a version
   of HarnessOptions with setters
   - Classloading: JMH's ClassUtils.loadClass() manually builds an
   URLClassLoader, which breaks classloader inheritance, but I don't know if
   there is a better option.

Regards,
Julien