Reachability: Add support for network checks

This patch is necessary to find out if network is reachable.
Network: Check to see if network is available

If network is not available, simply alert the user.
Project: Move library to appropriate folder

SystemConfiguration.framework should be in "Frameworks" folder.
SystemConfiguration.framework is necessary for Reachability
WIFI: require

set "wifi" (UIRequiresPersistentWiFi) flag for UIRequiredDeviceCapabilities