Fix dox for #1795, and improve !PyCml response to no config file.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@17990 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2312 Corrected line loop definitions to avoid holes in volume.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@17991 b5f69653-2bf5-0310-8201-b0dafb8e1405