removed i18n imports from zeroconf/connection files

that zeroconf connection should be used.
Create the neccessary config values if zeroconf
account is not present

removed some debug messages

added proper dispatch signals so contacts get shown
fixed some errors with roster data

(though something is wrong with it)

changed contact index to name@hostname

(fixes #1953 and maybe #1991)

Do not highlight in gc in case we are sure our nick is beginning of a real word (nick after = A->Z or a->z)

Fixes #1970.

when clicking on a contact in roster : remove duplicate code, also open awaiting events when middle clicking
instead of always open chat