added filter builder widget and filter tree

filter builder takes filter options from user, then adds
completed filters to the filter tree. the filter tree does
not currently do anything. in the future it will filter the
cards in the database view.

cockatrice/src/filterbuilder.h

@@ -0,0 +1,37 @@
+#ifndef FILTERBUILDER_H
+#define FILTERBUILDER_H
+
+#include <QFrame>
+
+class QCheckBox;
+class QComboBox;
+class QLineEdit;
+class CardFilter;
+
+class FilterBuilder : public QFrame {
+	Q_OBJECT
+
+private:
+	QComboBox *typeCombo;
+	QComboBox *filterCombo;
+	QLineEdit *edit;
+	CardFilter *fltr;
+
+	void destroyFilter();
+
+public:
+	FilterBuilder(QWidget *parent = 0);
+	~FilterBuilder();
+
+	bool filter(const CardFilter *f) const;
+
+signals:
+    void add(const CardFilter *f);
+
+public slots:
+private slots:
+	void add_released();
+protected:
+};
+
+#endif