Fix recursOn (I was over-optimizing and missed the fact that BYSETPOS worked differently), getPreviousDate (the UNTIL date of the RRULE is not necessarily a recurrence), and getPreviousValidDateInterval (simply round down to the next lower multiple of the frequency...)
Fix recursOn (I was over-optimizing and missed the fact that BYSETPOS worked differently), getPreviousDate (the UNTIL date of the RRULE is not necessarily a recurrence), and getPreviousValidDateInterval (simply round down to the next lower multiple of the frequency...)

svn path=/trunk/KDE/kdepim/; revision=422244

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