Allow specifying a custom matcher

We've been having problems using metrics-guice in DropWizard. Since we create the resources via guice, they are processed by metrics-guice before being handed over to Jersey. Unfortunately guice does not propagate annotations to the proxy and so Jersey does not thing the resources are in fact resources. See also https://groups.google.com/forum/#!msg/dropwizard-user/YA7pR5n_QUo/2Nk4IhKhIIMJ and 
https://github.com/dropwizard/metrics/issues/315 for additional info.

This change allows to specify a custom matcher when installing the metrics-guice module which allows us to 'hide' the resources from metrics-guice (and have metrics-jersey handle them instead).