Backport r933937 by smartins from trunk to the 4.2 branch:
Backport r933937 by smartins from trunk to the 4.2 branch:

A to-do is always 30 minutes tall, with endY at dtDue() and startY 30m before dtDue(), but if dtDue() was for example 00:20 then
startY would be displayed at 23h50 (and endY also at 23h50 because endY can't be smaller)

svn path=/branches/KDE/4.2/kdepim/; revision=933957

lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi