Update Doxyfile format

[hyanwong]

The changes here were created automatically by running doxygen -u in the doxygen directory.

Updating the format means that we don't get doxygen warnings on OS X installations any more.

[codecov]

Codecov Report

Merging #415 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #415   +/-   ##
=======================================
  Coverage   86.59%   86.59%           
=======================================
  Files          20       20           
  Lines       14141    14141           
  Branches     2756     2756           
=======================================
  Hits        12246    12246           
  Misses        977      977           
  Partials      918      918

Flag	Coverage Δ
#c_tests	87.71% <ø> (ø)	⬆️
#python_c_tests	90.49% <ø> (ø)	⬆️
#python_tests	99.3% <ø> (ø)	⬆️

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