AddressSpaceInfoManager: address space limit values have now proper names
AreaLimitBase: introduced an interface class for AreaLimit
AddressSpaceInfoManager: don't use accurate types in get*Limits functions

This allows to have a similar interface to all such functions.
AreaLimitManager: added ability to retrieve area limits from AddressSpaceInfoManager

AddressSpaceInfoManager has its own ASAreaLimit class of which
instances are passed back to AreaLimitManager.