[rules-dev] Calendaring support

[Mark Proctor]

I just got Calendars working, they can work in combination with timers, see:
http://blog.athico.com/2009/12/last-week-i-blogged-about-cron-and-int.html

I'm just adding start/end support to the timer functionality too. 
Feedback welcome. Unit tests are here:
http://fisheye.jboss.org/browse/JBossRules/trunk/drools-compiler/src/test/java/org/drools/integrationtests/ExecutionFlowControlTest.java?r=HEAD
testNoProtocolIntervalTimer
testIntervalTimer
testCronTimer
testCalendarNormalRuleSingleCalendar
testCalendarNormalRuleMultipleCalendars
testCalendarsWithCron
testCalendarsWithIntervals

Mark