Fix compilation: std::lower_bound is in <algorithm>

Change-Id: I5ab897725e47dba949c25cab5e5e3d4406ce4d8a
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/cpptools/includeutils.cpp

@@ -42,6 +42,8 @@
 #include <QTextBlock>
 #include <QTextDocument>
 
+#include <algorithm>
+
 using namespace CPlusPlus;
 using namespace CppTools;
 using namespace CppTools::IncludeUtils;