Scan through the Command directory looking for classes and see what commands they implement.
if FALSE (default), the new list of commands should replace the current one. If TRUE, new entries will be merged with old.
where (what directory) to look for classes, defaults to the Command subdirectory of the directory from where this file (__FILE__) is included.
Table 32-1. Possible PEAR_Error values
|Error code||Error value||Meaning||Solution|