Fixed #3632: session error while running several surveys at the same time in different browser windows.
Fixed #3080: submitting a survey closes sessions opened by other applications on the same server.

git-svn-id: file:///Users/Shitiz/Downloads/lssvn/source/limesurvey_dev@7605 b72ed6b6-b9f8-46b5-92b4-906544132732