Merge branch 'Fix_histogram_crash' into 'master'

Fixed crash on Histogram computation with no bins

See merge request !114

libs_required/ACG/QtWidgets/QtHistogramWidget.cc

@@ -78,7 +78,8 @@ void QtHistogramWidget::paintEvent(QPaintEvent *event) {
     const std::vector<double> &bin_widths = histogram_->getBinWidths();
     const double total_width = histogram_->getTotalWidth();
 
-    const size_t hist_max =  *std::max_element(bins.begin(), bins.end());
+
+    size_t hist_max =  bins.size() > 0 ? *std::max_element(bins.begin(), bins.end()) : 0;
 
     /*
      * Establish regions