Added logging module

lib/interaction.js

@@ -4,6 +4,7 @@
 import Interface from './interface.js'
 import { Points, Angle, MapProxy } from './utils.js'
 import Events from './events.js'
+import Logging from './logging.js'
 
 /** Interaction patterns
 
@@ -916,11 +917,6 @@ export class InteractionMapper extends InteractionDelegate {
         this.logInteractionsAbove = logInteractionsAbove
     }
 
-    log(message) {
-        let logger = (typeof app != 'undefined' && app.log) ? app : console
-        logger.log(message)
-    }
-
     get targetInterface() {
         return IInteractionMapperTarget
     }
@@ -943,7 +939,7 @@ export class InteractionMapper extends InteractionDelegate {
         let size = this.interaction.current.size
         let limit = this.logInteractionsAbove
         if (size > limit) {
-            this.log(`Number of interactions ${size} exceeds ${limit}`)
+            Logging.log(`Number of interactions ${size} exceeds ${limit}`)
         }
     }