AppConfig::State

* define() should accept a variable name parameter of the GetOpt::Long
  form: e.g. "foo|bar|baz=i@" and extract the relevant configuration
  information from it.

* Perhaps allow a callback to be installed which is called *instead* of
  the get() and set() methods (or rather, is called by them).

* CASE sensitivity may be required on a per-operation basis.  E.g. CASE
  sensitive for AppConfig::Args but CASE insensitive for AppConfig::File.

* Allow a state definition to supply additional sub-states that represent
  a [block] inside a configuration file.  This would permit one block to
  have a different policy (e.g. CREATE) from others.

* AppConfig::State may need to have CMDARG re-introduced.  When using
  blocks, it will be considerably more convenient to say '-v' rather
  than -block_verbose.  The global CMDARG could be '%c' to indicate 
  the first character.


AppConfig::Getopt

* Create AppConfig::Getopt module to delegate to Getopt::Long


AppConfig::Sys

* Consider moving platform-specific code out to separate per-platform
  modules.


Documentation

* Creation of AppConfig::File and AppConfig::Args object through the
  AppConfig object

* Expansion of variables in AppConfig::File


