update b8 to version 0.6.1

Class b8_storage_mysql does not get updated during this commit,
because our implementation already uses PDO_MySQL instead of
the old mysql API used by the offical b8 codebase's class and
the fix for the potential SQL injection is already included in
our PDO version.
Merge pull request #99 from Thoronador/feature-b8-0.6.1-update

update b8 to version 0.6.1