added new database field subscriber.institution; fixed list of contacts when using the extensions on multiple domains in the same installation; fixed the backend ics-invitation (subscriber list was empty)

git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/slub_events/trunk@77934 735d13b6-9817-0410-8766-e36946ffe9aa
attach csv file with subscribers to all admin emails

git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/slub_events/trunk@77939 735d13b6-9817-0410-8766-e36946ffe9aa