Feature Changes
---------------

- Variable substitutions now reflect option data written by recipes.

- A part referenced by a part in a parts list is now added to the parts
  list before the referencing part.  This means that you can omit
  parts from the parts list if they are referenced by other parts.

- Added a develop function to the easy_install module to aid in
  creating develop eggs with custom build_ext options.

- The build and develop functions in the easy_install module now
  return the path of the egg or egg link created.

- Removed the limitation that parts named in the install command can
  only name configured parts.

- Removed support ConfigParser-style variable substitutions
  (e.g. %(foo)s). Only the string-template style of variable
  (e.g. ${section:option}) substitutions will be supported.
  Supporting both violates "there's only one way to do it".

- Deprecated the buildout-section extendedBy option.