tasks now emit floats rather than integers

Simplifies code for tasks.

app/task/render/render.cpp

@@ -172,7 +172,7 @@ void RenderTask::Render(TimeRangeList range_to_cache, int divider)
 
           // Signal process
           counter++;
-          emit ProgressChanged(qRound(100.0 * static_cast<double>(counter) / static_cast<double>(nb_frames)));
+          emit ProgressChanged(static_cast<double>(counter) / static_cast<double>(nb_frames));
 
           j = download_futures.erase(j);
         } else {

app/task/task.h

@@ -135,9 +135,9 @@ signals:
    *
    * @param p
    *
-   * A value (percentage) between 0 and 100.
+   * A progress value between 0.0 and 1.0.
    */
-  void ProgressChanged(int p);
+  void ProgressChanged(double d);
 
 private:
   QString title_;