Fix render event when timeslotsPerHour is 1

[nbenitez]

Hi, I found a bug when implementig week calendar for my site, that is,
an event renders two lines of text (event time in one line, title in a
second line) and currently the logic is to render each of them on a
timeslot, so you need at least a timeslotsPerHour of 2 so the two
lines look fine, the case is I use a timeslotsPerHour of 1 with enough
height to show the two lines, but week calendar is not doing so.

The fix is for your master branch although I originally made the fix for
1.2.2 version (my project uses jquery 1.3.2).
I made two screenshots of before and after the patch:

Before: http://www.meneame.net/backend/media.php?type=post&id=696616&image.jpg
After: http://www.meneame.net/backend/media.php?type=post&id=696618&image.jpg

I also handle the case someone use one and small timeslotperhour(<26px)
in that case we keep current behaviour and only one line is shown.

I would also take the chance to request you about backporting some
patches to a jquery 1.3.2 branch, there's a lot of people like me that
use jquery-1.3.2 and for a reason (my projects use plugins that dont
have a jquery 1.4 version, and so I cant switch).. and not all patches
but important ones (like the daylight savings one..)

Thank you for an awesome jquery week calendar!