fixed @expectedException class names
fixed some typos
minor #9603 Fixed some typos (fabpot)

This PR was merged into the 2.2 branch.

Discussion
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Fixed some typos

Commits
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5c6edb3 fixed some typos
8d69bb5 fixed @expectedException class names
When getting the session's id, check if the session is not closed

This introduced a regression from #9246, with an incomplete fix ;
As the `started` flag on the NativeSessionStorage was not `true`
anymore when saving the session, the session id was always empty
when saving it, and thus when sending the `PHPSESSID` cookie