Remove unnecessary header include.
Updated fault impulse tests for interpolated meshes.
Added consistency check of fault mesh for FaultCohesiveKin.
Merge branch 'knepley/upgrade-petsc-interface' of github.com:geodynamics/pylith into knepley/upgrade-petsc-interface

* 'knepley/upgrade-petsc-interface' of github.com:geodynamics/pylith:
  Faults: Better consistency testing