BF: do not enable pyinotify backend if pyinotify is too old (Closes gh-80)

server/filterpyinotify.py

@@ -23,12 +23,18 @@ __author__ = "Cyril Jaquier, Lee Clemens, Yaroslav Halchenko"
 __copyright__ = "Copyright (c) 2004 Cyril Jaquier, 2011-2012 Lee Clemens, 2012 Yaroslav Halchenko"
 __license__ = "GPL"
 
+from distutils.version import LooseVersion
+
 from failmanager import FailManagerEmpty
 from filter import FileFilter
 from mytime import MyTime
 
 import time, logging, pyinotify
 
+if not hasattr(pyinotify, '__version__') \
+  or LooseVersion(pyinotify.__version__) < '0.8.3':
+  raise ImportError("Fail2Ban requires pyinotify >= 0.8.3")
+
 from os.path import dirname, sep as pathsep
 
 # Gets the instance of the logger.