change main font from signiak to source sans pro
use relative path for fonts
fix font path
add map files to gitignore
rename public font file
change background color
fix contact name padding
improve contact list style
improve contact header style
import: fix string case for address
improve import experience

* display loading message for big vcf files preview loading.
* for contact preview: display email as preview when no name is set.
improve ux of contact import

do not freeze navigator while importing a lot of contacts
improve contact widget style
improve note textarea style
import contact only if it is not present yet in the database
allow to export contact as a vcard
use locale comparison for contact name sorting
add missing translations
add test: import an already existing name
add test for vcf export of a single contact