fixed DateFormat of meetings and more enhancements

- fixed date/time display of meetings
- added function to determine room availability which returns meeting
end time if taken
- UI enhancements ( graphic, layouts, font sizes, simplified, etc)
Revert "fixed DateFormat of meetings and more enhancements"

This reverts commit 8a656d9c62543e4ba5314bea0a39da90b82865da.