Make Historymonitor.history a list instead of a deque (for slicing)

lib/tfw/components/history_monitor.py

@@ -1,6 +1,5 @@
 from watchdog.observers import Observer
 from watchdog.events import FileSystemEventHandler
-from collections import deque
 from os.path import dirname
 
 
@@ -17,7 +16,7 @@ class CallbackEventHandler(FileSystemEventHandler):
 class HistoryMonitor:
     def __init__(self, histfile):
         self.histfile = histfile
-        self._history = deque()
+        self._history = []
         self.observer = Observer()
         self.observer.schedule(CallbackEventHandler(self._fetch_history), dirname(self.histfile))
 
@@ -27,7 +26,7 @@ class HistoryMonitor:
 
     def _fetch_history(self):
         with open(self.histfile, 'r') as ifile:
-            self._history = deque(ifile.readlines())
+            self._history = ifile.readlines()
 
     def watch(self):
         self.observer.start()