Investigate improving synchronization mechanism between BaseTraceService and MessageLogHandler

[Channyboy]

Investigate improving synchronization mechanism between BaseTraceService/JsonTraceService and MessageLogHandler.

Currently, the synchronization mechanism is to lock on an shared object between the BaseTraceService/JsonTraceService and MessageLogHandler.

A synchronization mechanism is needed to avoid a deadlock that can occur between the two classes. This deadlock occurs when trace is set to *=all and occurs quickly during server start up.

The deadlock occurs due to the synchronized methods of FileLogHolder and a (previously) synchronized method synchronousWrite in MessageLogHandler which makes calls to FileLogHolder. Under a high trace volume, the synchronousWrite frequently locks (lock 1) on the calling thread. When a server configuration update is called, certain update logic is made to FileLogHolder through a separate thread (lock 2). This lock prevents any other threads that are trying to write via MessageLogHandler. Further into the update stack, a tracing event is emitted and is stuck waiting for lock 1 to unlock.