Apache::Config::Preproc reads and parses Apache server configuration file,
expanding the syntactic constructs selected by the -expand option.  In the
simplest case, the argument to that option is a reference to the list of
names.  Each name in the list identifies a module responsible for processing
specific Apache configuration keywords.  For convenience, most modules are
named after the keyword they process, so that, e.g. include is responsible
for inclusion of the files listed with Include and IncludeOptional
statements.
