Add Duck Duck Go to default search engines

This doesn't affect current users, only new or reset configurations.

data/search

@@ -1,28 +1,29 @@
+[Duck Duck Go]
+name=Duck Duck Go
+text=Privacy-aware Web Search
+uri=https://duckduckgo.com/?q=%s
+token=dd
 
 [Yahoo]
 name=Yahoo
 text=Yahoo Web Search
 uri=http://search.yahoo.com/search?p=
-icon=
 token=y
 
 [Google]
 name=Google
 text=Web Search
 uri=http://www.google.com/search?q=%s
-icon=
 token=g
 
 [Wikipedia]
 name=Wikipedia
 text=The free encyclopedia
 uri=http://en.wikipedia.org/wiki/Special:Search/%s
-icon=
 token=wp
 
 [TheFreeDictionary]
 name=The Free Dictionary
 text=Dictionary, Encyclopedia and Thesaurus
 uri=http://www.thefreedictionary.com/%s
-icon=
 token=fd