message: Update .gitignore
  A more extensive list of files that we do not want in the repo.
diff: -*.o
  -*.a
  +# ------------------------------------------------------------------------------
  +# List of file patterns we do not want in the repo.
  +# ------------------------------------------------------------------------------
  -examples/ex*
  -!examples/ex*.cpp
  -examples/*.mesh
  -examples/*.gf
  +# Object and library files
  +*.[oa]
  +*.so
  +*.dylib
  -miniapps/*/*.mesh
  -miniapps/*/*.gf
  +# Backup files
  +*~
  -config/_*
  -config/user.mk
  +# Totalview breakpoint files
  +*.TVD.*breakpoints
  +
  +# Mac related
  +*.dSYM
  +.DS_Store
  +
  +# Generated files in the root MFEM directory
  +/deps.mk
  +
  +# Generated files in config/
  +config/_config.hpp
  config/config.mk
  +
  +# Optional user configuration files in config/
  +config/user.cmake
  +config/user.mk
  +
  +# Generated documentation files in doc/
  +doc/CodeDocumentation.conf
  +doc/CodeDocumentation.html
  +doc/CodeDocumentation
  +
  +# Generated executables - examples and miniapps
  +examples/**/ex[1-9]
  +examples/**/ex[1-9]p
  +examples/**/ex[1-9][0-9]
  +examples/**/ex[1-9][0-9]p
  +miniapps/electromagnetics/joule
  +miniapps/electromagnetics/tesla
  +miniapps/electromagnetics/volta
  +miniapps/meshing/klein-bottle
  +miniapps/meshing/mesh-explorer
  +miniapps/meshing/mobius-strip
  +miniapps/meshing/shaper
  +miniapps/performance/ex[1-9]
  +miniapps/performance/ex[1-9]p
  +miniapps/tools/display-basis
  +
  +# Files generated by examples and miniapps
  +# (this list is based on 'clean' rules in makefiles)
  +examples/refined.mesh
  +examples/displaced.mesh
  +examples/**/mesh.*
  +examples/ex5.mesh
  +examples/**/Example5*
  +examples/**/Example9*
  +examples/Example15*
  +examples/**/Example16*
  +examples/sphere_refined.*
  +examples/**/sol.*
  +examples/**/sol_u.*
  +examples/**/sol_p.*
  +examples/**/ex9.mesh
  +examples/**/ex9-mesh.*
  +examples/**/ex9-init.*
  +examples/**/ex9-final.*
  +examples/**/deformed.*
  +examples/**/velocity.*
  +examples/**/elastic_energy.*
  +examples/mode_*
  +examples/**/ex16.mesh
  +examples/**/ex16-mesh.*
  +examples/**/ex16-init.*
  +examples/**/ex16-final.*
  +miniapps/electromagnetics/Volta-AMR*
  +miniapps/electromagnetics/Tesla-AMR*
  +miniapps/electromagnetics/Joule_*
  +miniapps/meshing/mobius-strip.mesh
  +miniapps/meshing/klein-bottle.mesh
  +miniapps/meshing/mesh-explorer.mesh
  +miniapps/meshing/partitioning.txt
  +miniapps/meshing/shaper.mesh
  +miniapps/performance/refined.mesh
  +miniapps/performance/mesh.*
  +miniapps/performance/sol.*
  