Cache the firstMonthOfSection value
Cache the numberOfWeeksInSection value
Use a lean model object to hold and draw the date labels

Draw the buttons by hand

Draw the buttons that should be visible

Use UILabels instead of UIButtons

Draw the correct background image

Use a custom cell object to hold label properties

Move the drawing code to the cell

Pre-compute the line height outside of the drawing loop

Rename the displayHelper class

Improve performances by not drawing the background manually (UIImageView is better at it).

We loose the benefit of having an opaque view for text rendering, but
it is faster overall.

Move the drawing code to the drawing helper view

Move the helper view code to TSQDayLabelCell

Rename TSQDayLabelCell to TSQLabelCell

Restore the cell selection

Optimize the delegate lookup

Optimize the label cell drawing code

Report label cells as accessibility elements

Move labels creation from layout to initialization

This helps to remove the labels creation weight from Instruments traces.

Document TSQLabelCell and TSQLabelCellsView properties and methods.
Merge branch 'performances'

This greatly reduces stuttering on older devices (iPhone 3G S and iPhone 4).
The TestApp stress test goes from 11 FPS to 36 FPS, and the framerate during regular use
is often higher.