Fetching, managing, and converting content
==========================================

The modules in the content directory provide the infrastructure for fetching
data, managing it in memory, and converting it for display.

Struct Content
--------------
Each URL is stored in a struct ::content. This structure contains the
content_type and a union with fields for each type of data (HTML, CSS,
images). The content_* functions provide a general interface for handling these
structures. For example, content_redraw() calls html_redraw() or
nsjpeg_redraw(), etc., depending on the type of content. See content.h and
content.c.

Fetching
--------
A high-level interface to starting the process of fetching and converting an URL
is provided by the fetchcache functions, which check the memory cache for a url
and fetch, convert, and cache it if not present. See fetchcache.h and
fetchcache.c.

The fetch module provides a low-level URL fetching interface. See fetch.h and
fetch.c.