Add regex bean matching, and regex key search/replace to normalize names

This patch adds two more config items to the JolokiaCollector.conf
mbeansre:  works like mbeans: but matches with regularexpressions
rewrite: which allows rewrite pairs in order to rename collected keys before data is passed to the handler
I might be misunderstanding, but won't this turn any metric that ends in `.init` into an empty string? Is that valid?