Calendar should be navigable via keyboard & pointing device

As discussed during the irc meeting, on the desktop the calendar should be navigable via the keyboard and mouse.

Suggested keyboard shortcuts:-

Month, Week & Day view
keyboard navigation: left/right for prev/next month/week/day, up/down to scroll
Mouse wheel to scroll up/down
Mouse wheel horizontal for prev/next month/week/day

Year view
keyboard navigation: up/down for prev/next row of months
Show 3 or 4 months per row, as space allows
Mouse-wheel scrolling currently doesn’t work properly (only works in one direction), this should be fixed.

Event details
keyboard navigation: escape to go back, ctrl+e to edit
Perhaps use 2 columns, title description and times on the left, map and attendees on the right
Guest list is cut off at the bottom if it’s too long, doesn’t scroll all the way

Edit Event/New Event
Datepicker should scroll with mouse wheel