Removed "style" from extra_hour and hour in view_calendar.c in order to let the css...

Removed "style" from extra_hour and hour in view_calendar.c in order to let the css kick in for events_of_the_day. Modified according css so that it looks as it as intended.
The hardcoded style overwrote the stuff in css (we have a few of these cases in calendar) and made the view stick to top:0 and left:0, which looked wrong.
Also made the td.events_of_the_day 50% width, works better for small and large viewports.
Additionally, made a:visited in .calendar look like unvisited links, since i think there is no real use for the difference.