add option to escape ampersand and percent signs in BibTex

[Former user]

Anonymous message posted by [e-mail]

It would be nice to have an option to escape ampersand and percent signswhen exporting to BibTex. As discussed here http://tex.stackexchange.com/questions/22179/error-with-percent-sign-in-bib-entry-field-when-using-biblatex-biber and here https://sourceforge.net/tracker/?func=detail&atid=1073792&aid=3372506&group_id=228270 some tools have problems with unescaped percent signs. The percent sign is quite frequent in the abstract field, the ampersand sign might appear in the journal title field. As a solution right now I have manually escaped all percent sings, these shoul not be escaped again.