QmlProfiler: Move timeline classes into own namespace

The new namespace "Timeline" is for classes that are supposed to go to
the generic timeline library later.

Change-Id: I1f6dce59de2c37398b1ed89473e1a94ec020104b
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

src/plugins/qmlprofiler/timelinerenderer.cpp

@@ -48,8 +48,7 @@
 
 #include <math.h>
 
-using namespace QmlProfiler;
-using namespace QmlProfiler::Internal;
+namespace Timeline {
 
 TimelineRenderer::TimelineRenderer(QQuickItem *parent) :
     QQuickItem(parent), m_model(0), m_zoomer(0), m_notes(0),
@@ -460,3 +459,4 @@ void TimelineRenderer::setRowCountsDirty()
     m_rowCountsDirty = true;
 }
 
+} // namespace Timeline