Adding Support for PermSpace

[tesonep]

• Having a new generation of objects, the permanent objects.
• Splitting the RememberedSet (From Old, From Permanent)
• New Image Format supporting extended format (Needed for saving permanent space).
• Primitives to move objects to perm space (single, bulk)
• Improving the comparison of old/new/perm object references.

By default, the new image format is not activated, so it is compatible with pharoX branch.

[tesonep]

~~I want to add the setting from outside the image format to use. Please don't merge yet.~~

[guillep]

Tests are green!