Player: move up timeline and adjust size

keep play button bar at the bottom for all configurations, avoid text and buttons overlay when Player is small. Fix cut timing in selection

Timeline.cpp

@@ -268,6 +268,28 @@ GstClockTime Timeline::sectionsDuration() const
     return duration() - d;
 }
 
+
+GstClockTime Timeline::sectionsTimeAt(GstClockTime t) const
+{
+    // target time
+    GstClockTime d = t;
+
+    // loop over gaps
+    for (auto it = gaps_.begin(); it != gaps_.end(); ++it) {
+        // gap before target?
+        if ( (*it).end < d ) {
+            // increment target
+            d += (*it).end - (*it).begin;
+        }
+        else
+            // done
+            break;
+    }
+
+    // return updated target
+    return d;
+}
+
 size_t Timeline::fillSectionsArrays( float* const gaps, float* const fading)
 {
     size_t arraysize = MAX_TIMELINE_ARRAY;