[development] DEP - cascading variable system

[Jeremy Epstein]

My number one feature request for variable handling in Drupal is this:

1. Every variable has its default value defined in ONE place (e.g.
perhaps inside hook_init() for each module, have function calls such
as "variable_define('some_value', 42);", where 42 is the default
value).
2. Remove that evil second argument from variable_get(). Default
values should not be repeated every time a variable is used.

Regarding the actual proposal of a cascading variable system, sounds
good to me! If variables can be overridden in multiple layers, in such
a way that module authors don't get really confused, that will
certainly improve the system.

Jaza.