PEAR_Config rewrite:

PEAR_Config rewrite:

* Now supports (in theory) an arbitrary number of
  config "layers" (different sets of configuration data with a defined
  priority).
* Specify the type of config values so different frontends can make
  user-friendly configuration interfaces.  Valid types are currently
  "string", "integer", "file", "directory", "set" and "password".  The
  set type lets you specify a limited set of values that the config
  values must be selected from.  Password values are stored
  base64-encoded.
* Added phpdoc comments and some docs for config values.
* Added singleton method.
# configuration files still contain serialized data