Reorganize ListView Display (sort under each date)

[Frostlight]

Instead of showing the date next to each entry in the ListView, sort entries into subheaders, each header showing the respective date with all the events occuring in that date

Before:
Event 1 --------------- 3pm Today
Event 2 --------------- 5pm Today
Event 3 --------------- 6pm Tomorrow

After:
Today
Event 1 --------------- 3pm
Event 2 --------------- 5pm

Tomorrow
Event 3 --------------- 6pm