In pull request #4644 a central MATHJAX_CODEFILE was introduced, but the snap rounding package was omitted, so this is corrected here.
For the MathJax V3 ( see #5707) this change is even mandatory (the current construct doesn't work).
When having a bit a long citation description, the description runs, in the HTML output on the bibliography page, into 3 or more lines where the 3rd and following lines continue underneath the citation number like:
```
[1] Eric Berberich, Arno Eigenwillig, Michael Hemmer, Susan Hert, Lutz Kettner, Kurt Mehlhorn, Joachim Reichel, Susanne Schmitt, Elmar Schömer, and Nicola Wolpert. Exacus: Efficient and exact
algorithms for curves and surfaces. In Gerth S. Brodal and Stefano Leonardi, editors, 13th Annual European Symposium on Algorithms (ESA 2005), volume 3669 of Lecture Notes in Computer Science,
pages 155–166, Palma de Mallorca, Spain, October 2005. European Association for Theoretical Computer Science (EATCS), Springer.
```
The example was found in e.g. https://doc.cgal.org/latest/Algebraic_foundations/citelist.html
- corrected the "overflow"
- made the citation number right aligned
When (re)generating the documentation from the sources and not using the, internally patched CGAL, doxygen version one gets messages about:
```
warning: ignoring unsupported tag 'EXTRACT_ALL_NO_DETAILED_IF_EMPTY'
```
By introducing the option `CGAL_EXTRACT_ALL_NO_DETAILED_IF_EMPTY` this doxygen setting can be steered
- option not supplied to cmake, will use as if specified `-DCGAL_EXTRACT_ALL_NO_DETAILED_IF_EMPTY=ON`
- option supplied to cmake as `-DCGAL_EXTRACT_ALL_NO_DETAILED_IF_EMPTY=ON` will write the line `EXTRACT_ALL_NO_DETAILED_IF_EMPTY = YES` in the doxygen configuration
- option supplied to cmake as `-DCGAL_EXTRACT_ALL_NO_DETAILED_IF_EMPTY=OFF` will write the line `#EXTRACT_ALL_NO_DETAILED_IF_EMPTY = NO` in the doxygen configuration, so just using the default setting of `NO` line could be omitted but it is better to have a placeholder