Revert "extends Tail in pure coffee"

This reverts commit 21db8f2e.

debomatic-webui/lib/tail.coffee

+"use strict"
 fs = require("fs")
 Tail = require("tail").Tail
+Tail::watchEvent = (e) ->
+    _this = this
+    if e is "change"
+        fs.stat @filename, (err, stats) ->
+            if err
+                _this.emit "error", err
+                return
+            _this.pos = stats.size if stats.size < _this.pos
+            if stats.size > _this.pos
+                _this.queue.push
+                    start: _this.pos
+                    end: stats.size
 
-class MyTail extends Tail
+                _this.pos = stats.size
+                _this.internalDispatcher.emit "next" if _this.queue.length is 1
 
-    watchEvent: (e) ->
-        if e is 'change'
-            stats = fs.statSync(@filename)
-            @pos = stats.size if stats.size < @pos #scenario where texts is not appended but it's actually a w+
-            if stats.size > @pos
-                @queue.push({start: @pos, end: stats.size})
-                @pos = stats.size
-                @internalDispatcher.emit("next") if @queue.length is 1
-        else if e is 'rename'
+    else if e is "rename"
         @unwatch()
-            @emit "error", "File " + @filename + " deleted."
+        _this.emit "error", "File " + @filename + " deleted."
+    return
 
-    close: () ->
+Tail::close = ->
     @unwatch()
     return
 
-module.exports = MyTail
+module.exports = Tail