php-cgi is now run without any command line arguments and information
such as the script filename and the query string are passed in via
environment variables.

This makes it possible to load image files, and doesn't spam write() as
much.

This new strategy involves finding the local file path for the given
URI, determining what method to use to fulfill the request (read file
from disk, use php-cgi, or error), then it writes the response to the
client socket.

The most significant change is that the functions for reading a file and
such write directly to the socket instead of attempting to fill buffers.

There are a bunch of helpful standard library functions that I am
missing out on (most notably popen)