added default ctor for maps etc.

sigh.. I hate to do this..

Change-Id: Icf5940c0e60d39a2a1a33fbf78d2af6deb729524

i18nlangtag/source/languagetag/languagetag.cxx

@@ -487,6 +487,18 @@ LanguageTag::LanguageTag( LanguageType nLanguage )
 }
 
 
+LanguageTag::LanguageTag()
+    :
+        mnLangID( LANGUAGE_DONTKNOW),
+        mbSystemLocale( false),
+        mbInitializedBcp47( false),
+        mbInitializedLocale( false),
+        mbInitializedLangID( false),
+        mbIsFallback( false)
+{
+}
+
+
 LanguageTag::LanguageTag( const OUString& rBcp47, const OUString& rLanguage,
                           const OUString& rScript, const OUString& rCountry )
     :

include/i18nlangtag/languagetag.hxx

@@ -76,6 +76,12 @@ public:
     /** Init LanguageTag with LanguageType MS-LangID. */
     explicit LanguageTag( LanguageType nLanguage );
 
+    /** Default ctor, init LanguageTag with LanguageType LANGUAGE_DONTKNOW.
+
+        To be able to use LanguageTag in maps etc., avoid otherwise.
+     */
+    explicit LanguageTag();
+
     /** Init LanguageTag with either BCP 47 language tag (precedence if not
         empty), or a combination of language, script and country.