corrected gmt time calculation

foursquare returns timezoneoffset in minutes, not hours …
this previous version would work too:
get_date_from_gmt(date('Y-m-d H:i:s', $checkin["createdAt"]))
Merge pull request #107 from danito/master

update fr translation and typo correction in moves.class.php
corrected de translation and expanded moves infographic
more german translation
added ajax_resync_items()

need some cleaning up and streamlining for import_tweets(). this
function should be more generic and work for both the ajax sync and the
regular or auto sync.
remove redundancy with the 2 separate import functions

a little less redundancy than previously
(0eb3199813bceafaf2df3495316a732fef7e5680), works with me, might need
some more testing though.

downsides:
* count counts all tweets ever, but the twitter API does not return all
tweets. aborts gracefully though.
* fav endpoint does not allow as many calls as the other apis. if
$count is set to 10 or 20 or even 50, not all favs can be grabbed befor
we hit the API limit (thats why there are 2 count limits, one for
normal calls, one for fav calls)
corrections to make the corrections of the last commit work
added ajax_resync_items()

fav sync not yet implemented because it requires authentication. i
didn't get hybridauth to autehnticate with flickr, but maybe the
oauth1.0a provider offers a way to to that.
update fr translation