Different kinds of log files are parsed by a collection of objects

Different kinds of log files are parsed by a collection of objects
of different classes, derived from the base class line_cooker
Depending on the message content or the message_type element in
XML, one of these objects is selected.

Logrunner is integrated with gcm_input. Although its functionality
is still limited, a connection between logrunner and gcm_input
is beginning to form.