Fix compile error with missing include

Signed-off-by: Geoff Hutchison <[email protected]>

avogadro/qtgui/richtextdelegate.cpp

@@ -1,21 +1,12 @@
 /******************************************************************************
-
   This source file is part of the Avogadro project.
-
-  Copyright 2015 Marcus Johansson <[email protected]>
-
-  This source code is released under the New BSD License, (the "License").
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
+  This source code is released under the 3-Clause BSD License, (see "LICENSE").
 ******************************************************************************/
 
 #include "richtextdelegate.h"
 
+#include <cmath>
+
 namespace Avogadro::QtGui {
 
 // See for example

avogadro/qtgui/richtextdelegate.h

@@ -1,17 +1,6 @@
 /******************************************************************************
-
   This source file is part of the Avogadro project.
-
-  Copyright 2015 Marcus Johansson <[email protected]>
-
-  This source code is released under the New BSD License, (the "License").
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
+  This source code is released under the 3-Clause BSD License, (see "LICENSE").
 ******************************************************************************/
 
 #ifndef AVOGADRO_QTPLUGINS_RICHTEXTDELEGATE_H