Merge pull request #17 from dokuwiki-translate/lang_update_97

Translation update (fr)
translation update
Merge pull request #18 from dokuwiki-translate/lang_update_103

Translation update (nl)
summarized trafic
fixed wrong grouping in viewport and resolution
don't count user screens twice

when a user arrives anonymously and then logs in, his resolution and
screen size was shown twice in the statistics. this should fix that
allow to configure which groups to log
upped version
translation update
Merge pull request #19 from dokuwiki-translate/lang_update_111

Translation update (fr)
some style fixes
fixed German language
count our own sessions

session garbage collection is unreliable on non-debian systems. Sessions
might live much much longer than the configured maximum age which
totally messes up all statistics based on them.

This introduce our own, timed session identifier (stored in the cookie).
Sessions should now die reliably after 15 minutes of inactivity.
don't log exits of expired sessions
translation update