#2349 removing more warnings found in osx gcc compiler

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18182 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2349 removing more warnings found in osx gcc compiler

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18183 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2323 Create a `BoxCollection` on construction of `NodesOnlyMesh`. Added a method to `AbstractMesh` for calculating the bounding box of arbitrary set of `Nodes`.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18184 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2323 Let `NodesOnlyMesh` increase the size of its underlying `BoxCollection` by adding a row / column / face of boxes at each extreme.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18186 b5f69653-2bf5-0310-8201-b0dafb8e1405