Grizzly support, incomplete Netty support

I can't get Netty to work, but I included the commit anyway.

I tested Grizzly by slightly modifying the `ninja-core-demo` (changed to `jar` packaging, added `src/main/webapp` as a `<resource>` mapped to `META-INF/resources`; I also used the `maven-shade-plugin` to build an executable uber-jar, but I think I only ever launched the server from within my IDE).
Note that one file is licensed under CDDL+GPL.

Feel free to do whatever you want with this code.