+=head2 C<header>
+
+Generates a general purpose http/html header and includes most of the scripts
+ans stylesheets needed.
+
+Only one header will be generated. If the method was already called in this
+request it will not output anything and return undef. Also if no
+HTTP_USER_AGENT is found, no header is generated.
+
+Although header does not accept parameters itself, it will honor special
+hashkeys of its Form instance:
+
+=over 4
+
+=item refresh_time
+
+=item refresh_url
+
+If one of these is set, a http-equiv refresh is generated. Missing parameters
+default to 3 seconds and the refering url.
+
+=item stylesheet
+
+=item stylesheets
+
+If these are arrayrefs the contents will be inlined into the header.
+
+=item landscape
+
+If true, a css snippet will be generated that sets the page in landscape mode.
+
+=item favicon
+
+Used to override the default favicon.
+
+=item title
+
+A html page title will be generated from this
+