Added notes on what needs updating.
Merge branch 'knepley/upgrade-petsc-interface' of github.com:geodynamics/pylith into knepley/upgrade-petsc-interface

# By Matthew G. Knepley
# Via Matthew G. Knepley
* 'knepley/upgrade-petsc-interface' of github.com:geodynamics/pylith:
  Faults: Changing from Lagrange vertices to hybrid edges

Conflicts:
	libsrc/pylith/faults/FaultCohesiveLagrange.cc