Rephrase, reformat and sync example dup configuration.

examples/example.dup

@@ -147,6 +147,14 @@ exclude = /home/*/.gnupg
 ## Default: 
 # incremental = yes
 
+## how many days of incremental backups before doing a full backup again ;
+## default is 30 days (one can also use the time format of duplicity).
+## if increments = keep, never automatically perform a new full backup ; 
+## only perform incremental backups.
+##
+## Default:
+# increments = 30
+
 ## how many days of data to keep ; default is 60 days.
 ## (you can also use the time format of duplicity)
 ## 'keep = yes' means : do not delete old data, the remote host will take care of this

handlers/dup.helper.in

@@ -408,10 +408,10 @@ EOF
 # if incremental = no, perform a full backup in order to start a new backup set
 incremental = $dup_incremental
 
-# how many days of incremental backups before doing a full backup again ; default is 30 days.
-# (you can also use the time format of duplicity)
-# if 'increments = keep' is set : do not start another full backup,
-# but keep doing incremental backups
+# how many days of incremental backups before doing a full backup again ;
+# default is 30 days (one can also use the time format of duplicity).
+# if increments = keep, never automatically perform a new full backup ; 
+# only perform incremental backups.
 #increments = 30
 #increments = keep
 increments = $dup_increments