Change how we check doxygen version

We used to check that we got exactly "1.8.14", but now we get
"1.8.16 (b4ba8f5*)", so we just check
that it starts with "1.8.16".

Author: Owen

scripts/run_doxygen.sh

@@ -2,7 +2,7 @@
 
 # Check doxygen version
 EXPECTED_VERSION="1.8.16"
-doxygen --version | grep -x $EXPECTED_VERSION > /dev/null
+doxygen --version | grep ^$EXPECTED_VERSION > /dev/null
 if [ $? -ne 0 ]
 then
   echo "WARNING: Using wrong version of doxygen.\