#2370 We added the !AbstractContractionCellFactory and tested it in !TestAbstractContractionCellFactory.hpp

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18888 b5f69653-2bf5-0310-8201-b0dafb8e1405
#1902 a bit of coverage

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18893 b5f69653-2bf5-0310-8201-b0dafb8e1405