The current Year view drawing routine gathers events
every single time we draw the navigator. This is, to
the best case, slow to death. In fact, this is why
year view's navigator is so memory and processor
consuming.
To fix that, cache the added components and simply
query them at drawing time.
When dragging events around, the cursors show a + as opposed to a
an arrow indicating that the event is being moved. This can confuse
users.
The fix is to tell GTK that the drag being performed is a move.
https://bugzilla.gnome.org/show_bug.cgi?id=774922
The Week view exposed a bug where we had different
CSS selectors for the exact same label. This made
them look inconsistent, with different colors and
paddings.
Fix that by ensuring they all use the same style
class. The Year view drawing code needed to be
reworked a little.
https://bugzilla.gnome.org/show_bug.cgi?id=778391