Merge pull request #2 from 52North/master

merge master
Merge pull request #78 from 52North/develop

Develop
create a exportController which provides a downloadable csv-file for every time series in the legend
Merge branch 'develop' into export
fix bug issue #84 permalink timespan=today&yesterday returns today only
Merge pull request #85 from irceline/master

fix bug issue #84
Merge branch 'master' of https://github.com/52North/js-sensorweb-client into develop
Merge branch 'export' into develop