adds clear button to line edits on 'add FX' and 'side bar browser' (#3329)

src/gui/EffectSelectDialog.cpp

@@ -122,6 +122,7 @@ EffectSelectDialog::EffectSelectDialog( QWidget * _parent ) :
 
 #if QT_VERSION >= 0x050000
 #define setResizeMode setSectionResizeMode
+	ui->filterEdit->setClearButtonEnabled( true );
 #endif
 	ui->pluginList->verticalHeader()->setResizeMode(
 						QHeaderView::ResizeToContents );

src/gui/FileBrowser.cpp

@@ -86,6 +86,9 @@ FileBrowser::FileBrowser(const QString & directories, const QString & filter,
 	opl->setSpacing( 0 );
 
 	m_filterEdit = new QLineEdit( ops );
+#if QT_VERSION >= 0x050000
+	m_filterEdit->setClearButtonEnabled( true );
+#endif
 	connect( m_filterEdit, SIGNAL( textEdited( const QString & ) ),
 			this, SLOT( filterItems( const QString & ) ) );