FactoryContext holds the Handlers configuration

- Decorators use this place to store their configuration, instead of
  having specific FactoryContext class fields
- Factory context is stored in its bean form instead of a dictionary
  form (to allow special types in handlers configuration)
- Code still to be cleaned up a bit
Contexts: code clean up

- Removed dictionary form methods
- Removed previous specific fields for requires and provides
- Added custom support of deep copy in Requirement
Removed dictionary form of FactoryContext

The FactoryContext bean is stored as is in manipulated class, instead of
being converted in a temporary dictionary.
The "factory context data" field (containing the dictionary) has been removed.
Call RequestHandler.finish() when exiting RemoteShell loop
Added a missing return...
iPOPO Core ignores classes with a partial FactoryContext

Case of parent classes of some factories, e.g. with an iPOPO property
decorator, but no factory name.
Corrected is_from_parent() method

The equality comparator of FactoryContext is less deep than before.
The 'is' keyword is now used to look if a bean is from a parent class or
not.
Updated tests for the new context beans

- Removed dictionary form tests
- Replaced handlers configuration access