• Allow customization of actions.
• Helm is now splitted in two packages helm-core and helm.
• Allow rewinding the C-l operations in `helm-find-files'.
• Helm use now only one help command bound to `C-h m'.
  The generic help is always displayed after the local help.
• Reorganisation of code in different files helm-lib and helm-types to
  allow usage of helm-core alone.