Add option for regexps in the transferlist search filter's context menu

src/base/preferences.h

@@ -350,6 +350,8 @@ public:
     void setTransSelFilter(const int &index);
     QByteArray getTransHeaderState() const;
     void setTransHeaderState(const QByteArray &state);
+    bool getRegexAsFilteringPattern() const;
+    void setRegexAsFilteringPattern(bool checked);
     int getToolbarTextPosition() const;
     void setToolbarTextPosition(const int position);