add ext_icon.gif #83

uses glyph from https://github.com/subugoe/sub-iconfont
Field Partials: allow prefixing the field content

using the prefixString variable
edfu: add WB page information to the short display

#83
improve rendering of fields

* put prefixString in the right place
* do not render nonexistant fields
edfu: use prefix string in GL index display

for better consistency with WL
edfu: en localisation for »ohne Suffix« checkbox
edfu: improve :hover on Details link
edfu: update facet labels
edfu: fix extra loading for data

(was messed up when loading several files)