Fixed css styles for foreground and background

Module generated always an empty css style 'color:#' and 'background-color:#', generation of opacity was wrong.
Fixed css styles for foreground and background
Fixed index of timetable hours array
Merge pull request #6 from thkuhn/hotfix/timetable-calendar-color-styles

Fixed css styles for foreground and background
Merge pull request #7 from thkuhn/hotfix/timetable-position-of-events

Fixed index of timetable hours array