fix for bug #188939. remove "unknown" and "not junk" as search and mailview criteria choices.

we remove "unknown" because the user never sees anything that distinguishes unknown from not junk.
being left with just junk and not junk, we remove not junk, because that's just "isn't junk"
r/sr=bienvenu, a=asa

suite/locales/en-US/chrome/mailnews/messenger.properties

@@ -179,10 +179,9 @@ forwarded=Forwarded
 new=New
 read=Read
 
-unknown=Unknown
+# for junk status picker in search and mail views
 junk=Junk
-notjunk=Not Junk
-
+# for the has attachment picker in search and mail views
 hasAttachments=Has Attachments
 
 # mailnews.js