#2536 - fix creating `OutputFileHandler` when asking for the root output folder and it has not yet been created.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@21712 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2536 - revert files committed accidentally in r21712.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@21713 b5f69653-2bf5-0310-8201-b0dafb8e1405
Make cell_id tests independent of their order in the test suite.  See r21673/r21677 on #2441 where moving a single test caused later tests to break.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@21717 b5f69653-2bf5-0310-8201-b0dafb8e1405
Oops.  Missing files from r21717.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@21718 b5f69653-2bf5-0310-8201-b0dafb8e1405