[petsc-dev] removing sieve

[Jed Brown]

Matt, I take it that you intend for this removal to be merged for
petsc-3.4 so that users are not distracted by something we aren't
supporting.  An alternative would be to add a #warning to petscdmmesh.h.

If we are deleting it from petsc-3.4, there are a few files that can
have more stuff deleted:

$ git grep -l 'ALE::'                                                                                                                           
bin/processSummary.py
config/PETSc/FEM.py
src/dm/impls/plex/plexfem.c
src/docs/doxygen/Doxyfile
src/snes/examples/tutorials/ex72.c


We can delete the sieve-dev mailing list and reference to it.

src/docs/website/miscellaneous/mailing-lists.html:          <td>: For Sieve users</td>


Update the FAQ to recommend DMPlex.

src/docs/website/documentation/faq.html:          use the Sieve construct in PETSc, this is a high

Remove src/docs/tex/manual/sieve.tex


Sieve is also referenced from src/docs/strategy.tex, which is an
outdated personal fragment that should probably also be deleted.