Move IEditor::isTemporary to IDocument

It's a property of the document implementation, not of the specific
editor instance working on it.

Change-Id: I5c3dd054e21b646e2d94b891916a096d045923f8
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/coreplugin/idocument.h

@@ -88,6 +88,8 @@ public:
     void setDisplayName(const QString &name);
 
     virtual bool isFileReadOnly() const;
+    bool isTemporary() const;
+    void setTemporary(bool temporary);
 
     virtual QString defaultPath() const = 0;
     virtual QString suggestedFileName() const = 0;
@@ -122,6 +124,7 @@ signals:
 private:
     QString m_filePath;
     QString m_displayName;
+    bool m_temporary;
     QString m_autoSaveName;
     InfoBar *m_infoBar;
     bool m_hasWriteWarning;