If a von-prefix occurs, add all the first letters to the shortened name, e.g.
"Jeroen van de Graaf", Crypto 2010 => C:vdGraaf10
Some names have been updated, but the labels were still outdated, e.g.
[EC:Burmester90a] => [EC:BurDes90]
Delicate care is taken into account that some keys were colliding so a "dis"-disambiguation is added, e.g.
[EPRINT:UnrDom12] & [EPRINT:Unruh12] => [EPRINT:Unruh12a] & [EPRINT:Unruh12b]
Various name fixes related to accents (and Tommaso d'Orsi).
Fixes more than what is discussed in pull request https://github.com/cryptobib/db/pull/252:
Closes: #252