Calendars don't work, when we work with two KieContainers

Description of problem:
Calendars don't work, when new KieContainer is created and newKieSession is called right after creation of other KieContainer and calling getKieBase.

Version-Release number of selected component (if applicable):
Drools 6.0.0-SNAPSHOT
6.0.0.ER2

How reproducible:
Pull request #251 submited in Drools.

Steps to Reproduce:
1. Make drl file with two rules. First rule should fire only on weekdays. Second rule should fire only on weekend days.
2. Write a test with this order of commands:

• create first KieContainer and call getKieBase()
• create second KieContainer
• from second KieContainer create new session ( newKieSession() )
• add calendars to session and call fireAllRules()
  3. Run test.

Actual results:
Two rules are fired.

Expected results:
Only one rule should fired.

Additional info: