Removing unused local.
Change `has' semantic and add a new request `is obtainable'.

`had' remove detachable mark and test factory existing.

`is obtainable' take care of the attachment mark.
Detachable type are directly satisfied.

Move `can_satisfy' implementation to IOC_INJECTOR and use `is_obtainable'.
Hide features inherited of {REFLECTOR}
Add a test for `is_obtainable'.