Merge branch 'baagaard/fix-meshing-examples-trelis'

* baagaard/fix-meshing-examples-trelis:
  Update configure.ac for obsolete directories (removed).
  Updated spline creation for compatibility with Trelis.
  Fixed typo in comment.
Merge commit '2bae13870c3a01dd4a1acceca3c441956f78eb01'

* commit '2bae13870c3a01dd4a1acceca3c441956f78eb01':
  Field: Setup DM field objects
  Solver: Remove DM from Vecs used in MatNullSpace - This avoids a reference cycle
Merge branch 'baagaard/add-missing-files-dist'

* baagaard/add-missing-files-dist:
  Added files to Makefile.
  Added files to Makefile.
Merge branch 'baagaard/add-examples-debugging'

* baagaard/add-examples-debugging:
  Added README to examples/debugging.
  Added debugging to examples Makefile. Updated filenames in debugging Makefile.
  Accidentally removed errors.
  Finished setting up files with error and correct files. Moved correct files to correct directory.
  Add more errors into mat_elastic and step02.
  Small adjustments to errors.
  Introduce some errors into spatialdb file.
  Cleanup some error messages.
  Added files for examples/debugging.
  Started work on debugging examples.
  Small improvements to 2-D gravity example.
  Finished setting up gravity example. Need to have Brad and Matt test it.
  Removed spatial database files that are created by python script.
  Delete log files I didn't mean to include.
  Added README.
  Added initial version of 2D gravity example
Merge branch 'baagaard/add-release-2.0.2'

* baagaard/add-release-2.0.2:
  Incremented version number and updated README.
Improved some error messages.

Also did some minor code cleanup.
Merge branch 'baagaard/fix-error-messages' into maint

* baagaard/fix-error-messages:
  Improved some error messages.