Merge pull request #473 from gabalafou/fix-debug-ie9

Fix broken logDebug() in IE9 and below

Author: benvinegar

src/raven.js

@@ -1081,7 +1081,12 @@ Raven.prototype = {
 
     _logDebug: function(level) {
         if (this._originalConsoleMethods[level] && this.debug) {
-            this._originalConsoleMethods[level].apply(this._originalConsole, [].slice.call(arguments, 1));
+            // In IE<10 console methods do not have their own 'apply' method
+            Function.prototype.apply.call(
+                this._originalConsoleMethods[level],
+                this._originalConsole,
+                [].slice.call(arguments, 1)
+            );
         }
     },