#2327 Some more work on the `CellBasedPdeHandlerOnCuboid` class 

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18820 b5f69653-2bf5-0310-8201-b0dafb8e1405
#1902 fix a small bug in `NodesOnlyMesh` with the constuction of the box collection when the domain size isnt divisible by the box width.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18822 b5f69653-2bf5-0310-8201-b0dafb8e1405