Generate poll-urls via model_url

Fixed Bug to wrong poll urls
Fixed #823
Start Browser on custom IP, fixed #827
Merge pull request #832 from normanjaeckel/Fix_Start_Option

Start Browser on custom IP, fixed #827
Merge pull request #831 from ostcar/issue-823

Generate poll-urls via model_url
Added Czech translation (Thanks to Pavel Fric!)
Merge pull request #835 from emanuelschuetze/czech-translation

Czech translation