[TYPO3-ttnews] Add and substitute marker with typoscript

[Tapio Markula]

Martin Schmidt kirjoitti:
> Hmm...ok, thank you.
> So I figure I start off best by examining i.e. "chcnewscon" to get an idea 
> how this hook thing works.

Define for this class file and related class into that file

$GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['tt_news']['extraItemMarkerHook'][]=...

into ext_localconf.php

extraItemMarkerProcessor
is the function name inside the class file

function extraItemMarkerProcessor(....

note that class name must start with tx_ or user_