Install examples for configuration with nginx and FastCGI

* debian/munin.examples: Install examples files.

* debian/munin.nginx.conf: Configuration sample for nginx.

* debian/munin-cgi.conf: Configuration to disable generation of html and
  graphs, should be put under /etc/munin/munin-conf.d/.

* debian/munin-cgi-graph.init: Init script to start munin-cgi-graph.

* debian/munin-cgi-html.init:  Init script to start munin-cgi-html.
move nginx examples to examples/nginx
debian/changelog entry for the last two commits
release as 2.0.17-2 to Debian sid