Move color to TimelineMarker and make sure all instances of a marker update on color change

app/timeline/timelinemarker.cpp

@@ -27,7 +27,8 @@ namespace olive {
 TimelineMarker::TimelineMarker(const TimeRange &time, const QString &name, QObject *parent) :
   QObject(parent),
   time_(time),
-  name_(name)
+  name_(name),
+  color_(7) // FIXME: set via config
 {
 }
 
@@ -53,6 +54,18 @@ void TimelineMarker::set_name(const QString &name)
   emit NameChanged(name_);
 }
 
+int TimelineMarker::color()
+{
+  return color_;
+}
+
+void TimelineMarker::set_color(int c)
+{
+  color_ = c;
+
+  emit ColorChanged(color_);
+}
+
 void TimelineMarkerList::Save(QXmlStreamWriter *writer) const
 {
   foreach (TimelineMarker* marker, markers_) {