Serve static content from Karyon

Initial implementation for serving static content from Karyon based on https://github.com/netty/netty/blob/master/example/src/main/java/io/netty/example/http/file/HttpStaticFileServerHandler.java.  

This solution honor's Jersey's 'com.sun.jersey.config.property.WebPageContentRegex' configuration property to match the static content regex and serve the contents via an HttpRequestRouter implementation.

To enable set the following property in the kayron configuration file.  

```
com.sun.jersey.config.property.WebPageContentRegex=([^\s]+(\.(?i)(img|js|css|htm|htm))$)|(/.*\.jsp)|(/WEB-INF/.*\.jsp)|(/WEB-INF/.*\.jspf)|(/.*\.html)|(/favicon\.ico)|(/robots\.txt)
```

The pull request also provides a solution to properly load jersey properties from archaius.  #79
I think RxNetty should provide a writeFile() method on the response to handle this case. This means we bring the file contents in memory (as you noted)