SNES: Added empty optimal control example
PetscFE: Added PetscFECreateDefault()
- Should replace element creation in examples with this
DMPlex: Respond to -dm_refine in DMSetFromOptions_Plex()
- Should change -da_refine to -dm_refine
- Problem since we create a new DM upon refinement, so we have to play games switching back ends
SNES ex13: Added element and section creation
- Have fields for state, adjoint, and control
- I used an easy way to define the control only on the boundary, may want to switch to subDM
SNES ex13: Added tests for P1 and refinement
PetscDualSpace: Added doc for PetscDualSpaceApply()
SNES ex13: Cleanup
- Made functions static
- Added P2 test
- Removed diagnostic print
- Explicit size for exactFuncs
SNES ex13: Starting to define problem
- Checked that exact solution is correct
Merge branch 'jed/python3-binaryio' into maint

* jed/python3-binaryio:
  bin/pythonscripts: fix string type checking for Python-3
  bin/pythonscripts: updated petsc_conf.py and PetscBinaryIO.py to be compatible with Python 3
Merge branch 'jed/fix-MatNullSpaceCreateRigidBody' into maint

* jed/fix-MatNullSpaceCreateRigidBody:
  MatNullSpaceCreateRigidBody: fix array length for 3D
Merge branch 'maint'
fix %d that should be %D
Merge branch 'barry/fix-percent-d' into next
update docs to emphasis building PETSc with C compiler, not C++
Merge branch 'master' into next
fix for removal of fortran checks in languages.py
add journal paper mszm2013 to petscapp.bib
Merge branch 'master' into next
Merge branch 'master' of bitbucket.org:petsc/petsc
petscapp.bib: add D'Amore 2011

Thanks-to: Luisa Carracciuolo <luisa.carracciuolo@cnr.it>