Documentation problems

[EltonCN]

Some documentation is wrong or lacking:

• Codelet.getBroadcast: return type is Memory, but documentation says list.
• RawMemory.RawMemory: typo "Crates" -> "Creates"
• MemoryObserver: no documentation
• RESTMemoryContainer: no class documentation
• RESTMemoryObject: no class documentation
• CodeletContainer: no class documentation. some methods without documentation.
• CodeRack: The class documentation is not very explanatory. Possibly split the references section from the explanation of what the class does.
• CodeRack.insertCodelet: is not creating a codelet, only inserting it.
• CodeRack.shutDown: is not stopping the CodeRack's thread, only the codelets threads.