Revert "Ticket #167 - Mixing transaction and non-transaction plugins can cause deadlock"
    
    This reverts commit 77fdecc3a2bf6d9ce8e545ba0746f619fb14ce84
    This is a partial revert.  We still want to keep the code in the plugins
    that allows them to be either a regular plugin or a betxn plugin.  All
    of the code that dealt with SLAPI_TXN and making sure all internal
    operations had SLAPI_TXN set is gone.  We will
    come up with a new mechanism for keeping track of the original requestor
    DN, most likely a scheme using Thread Local Storage (TLS).