updated the DTReachability so that normal an instance ob this class can be created.
The reason is that it is easier for unit testing, that the reachability can easily replaced stubs or mock implementations.
fixed Reachability demo for Xcode 4.x
cleanup
Change deployment target for Reachability demo
added that the hostname can be set and changed
Merge branch 'reachabilityAsInstance' of github.com:Cocoanetics/DTFoundation into reachabilityAsInstance

Conflicts:
	Core/Source/DTReachability/DTReachability.h
	Core/Source/DTReachability/DTReachability.m
removed duplicated code
fixed notification that self is passed instead of observers
replaced deprecated SCNetworkConnectionFlags
change to use the DTReachabilityInformation object instead of the flags
fixed reachable demo
Merge remote-tracking branch 'origin/reachabilityAsInstance' into develop

Conflicts:
	Core/Source/DTReachability/DTReachability.h
	Core/Source/DTReachability/DTReachability.m
Merge branch 'DTReachabilityInformation' into develop
Cleanup comments and code style