Logging changes

- Adds `Logging` protocol
- Moves to Swift-style `OSLog` usage

os_log to Logger

os_log audit

Replacment of os.log with Logging

iOS/ErrorHandler.swift

@@ -8,24 +8,21 @@
 
 import UIKit
 import RSCore
-import os.log
 
-struct ErrorHandler {
-
-	private static var log = OSLog(subsystem: Bundle.main.bundleIdentifier!, category: "Application")
+struct ErrorHandler: Logging {
 
 	public static func present(_ viewController: UIViewController) -> (Error) -> () {
 		return { [weak viewController] error in
 			if UIApplication.shared.applicationState == .active {
 				viewController?.presentError(error)
 			} else {
-				ErrorHandler.log(error)
+				log(error)
 			}
 		}
 	}
 		
 	public static func log(_ error: Error) {
-		os_log(.error, log: self.log, "%@", error.localizedDescription)
+		ErrorHandler.logger.error("\(error.localizedDescription, privacy: .public)")
 	}
 
 }