convert special characters from LaTeX and back

[Robert Jäschke]

On import a user might want to have Umlauts ({"u}) and other special chars converted from LaTeX to Unicode. Contrary, on export one might want to have LaTeX-compatible characters instead of Unicode.

This should be implemented as a user setting, such that the user can turn this feature on and off (separate for im-/export).

[Robert Jäschke]

Alternatively (the better one, I think), we should add this as an export option, like CiteULike does.

[Oliver Kopp]

Die Bibliothek “latex2unicode” (https://github.com/tomtung/latex2unicode) leistet hierfür hervorragende Arbeit. Sie ist in JabRef seit Jahren erfolgreich im Einsatz.