Support RDNSS and DNSSL
Fix README.md
Merge pull request #1 from mcanevet/dns

Add supoort for RDNSS and DNSSL
Add support for routes
Update tests
Add support for clients
Refactor configuration: Add radvd::config class

This also fixes some dependency quirks so that you now don't need to
explicitly include the radvd class anymore.
Make sure the latest version of radvd is installed
Add new simple test
Refactor README.md

 * Add a new simple example
 * Fix some wording
 * Add Current Status and TODO section
Release 0.2.0
Release 0.2.1