Remove Q_OBJECT macros and friend declaration from *Filter classes

Since these classes do not possess any signals/slots,
these macro are unnecessary.

Likewise, the friend declaration in TagFilter is useless,
since the corresponding fields are in the base class.

Fallout of commit 1a4e7ad0dd29b9eeac2016933cb86bff260dadbb.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

desktop-widgets/simplewidgets.h

@@ -177,32 +177,26 @@ protected:
 };
 
 class TagFilter : public FilterBase {
-	Q_OBJECT
 public:
 	TagFilter(QWidget *parent = 0);
-	friend class MultiFilter;
 };
 
 class BuddyFilter : public FilterBase {
-	Q_OBJECT
 public:
 	BuddyFilter(QWidget *parent = 0);
 };
 
 class SuitFilter : public FilterBase {
-	Q_OBJECT
 public:
 	SuitFilter(QWidget *parent = 0);
 };
 
 class LocationFilter : public FilterBase {
-	Q_OBJECT
 public:
 	LocationFilter(QWidget *parent = 0);
 };
 
 class TextHyperlinkEventFilter : public QObject {
-	Q_OBJECT
 public:
 	explicit TextHyperlinkEventFilter(QTextEdit *txtEdit);