Generate configuration files for apache and nginx 

This pull implements generating apache and nginx configuration files for testing purposes

You can generate an nginx configuration file using:

    ./cli.py pagespeed.debug.pyconf nginx [directive] > test.nginx.conf

This can be tested using, for example:
 
    /usr/local/nginx/sbin/nginx -t -c <path_to>/test.nginx.conf


An apache configuration file can be generated using

    ./cli.py pagespeed.debug.pyconf apache [directive] > test.apache.conf