Petals ESB Container

Currently, in the container directory:

• implementations are dezipped in the implementations subdirectory of the lib directory in a hierarchy of directories. For example the default registry implementation is in lib/implementations/registry/default.
• extensions are dezipped in the extension directory, next to the lib directory, altogether in it (all the jars are together).

To uniformise that, we should:

• put implementations in the same subdirectory, but with one directory per implementations, and no recursive subdirectories in them.
• put extensions in the same directory, but with one directory per extension and no recursive directory in them.

It will ease understanding of the directory structure and make things clearer and better organised.