Add an include to help Eclipse code analysis.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@19164 b5f69653-2bf5-0310-8201-b0dafb8e1405
#1157 Start writing XDMF master file with xerces-c

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@19165 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2397 Failing Test

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@19167 b5f69653-2bf5-0310-8201-b0dafb8e1405