Fix typos in comments

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Fix typos in error messages

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Fix typo in css code

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Merge pull request #13 from stweil/master

Typo fixes