Description
This sets an install-time complex search-and-replace function  allowing the setting of platform-specific variables in an  installed file.
if $type is php-const, then $to must be the name of a PHP Constant.  If $type is pear-config, then $to must be the name of a PEAR config  variable accessible through a PEAR_Config::get() method.  If  type is package-info, then $to must be the name of a section from  the package.xml file used to install this file.