#2130 Revert r18059 because the sparsity structure changes too much.  Add PETSc 3.3 specific line search code.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18078 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2116 mend nightly test, hopefully.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18082 b5f69653-2bf5-0310-8201-b0dafb8e1405