use Database-Transactions
added protection against multiple transaction-starts
added function documentation
transaction-support for PostgreSQL added
tidier implementation + bugfix
each request should be a transaction
Transaction functions throw dbExceptions now
committing a Transaction is done now within try-block
copy and paste errors corrected
begin_transaction in mysqli started in php5.5 - alternative implemented
another typo
Move beginTransaction
Merge pull request #1 from mattab/patch-1

Move beginTransaction
rename variable according coding standard
secure transactions against nesting
reverted Pgsql.php to old state ( unsupported )
fix missing paranthesis
Refactor visitor recognition in his own class, so that a third party plugin could reuse it.
IsVisitorKnow() wasn't support, this commit fixes the bug.
Fix typo
refs #5222 completely delete the Zeitgeist plugin
refs #5253 this might fix the database usage error. It definitely fixes nothing is displayed once you change a column in the graph charts since it does not support them. The summary configuration was never applied due to a typo.