first pass at converting the filters for python 2/3 compat

src/filters/rcldia

@@ -1,5 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
+from __future__ import print_function
+
 # dia (http://live.gnome.org/Dia) file filter for recoll
 # stefan.friedel@iwr.uni-heidelberg.de 2012
 #
@@ -66,7 +68,7 @@ class DiaExtractor:
         try:
             docdata = self.ExtractDiaText()
             ok = True
-        except Exception, err:
+        except Exception as err:
             ok = False
         iseof = rclexecm.RclExecM.eofnext
         self.em.setmimetype("text/plain")
@@ -76,7 +78,7 @@ class DiaExtractor:
     def openfile(self, params):
         try:
             self.dia = GzipFile(params["filename:"], 'r')
-            # Dial files are sometimes not compressed. Quite weirdly,
+            # Dia files are sometimes not compressed. Quite weirdly,
             # GzipFile does not complain until we try to read. Have to do it
             # here to be able to retry an uncompressed open.
             data = self.dia.readline()