use native int for backlog property
use native int for backlog property
doc comment correction
added private modifier to mutable fields
added static and final modifier to PreSerializationTransformer field

The LoggingEventPreSerializationTransformer is completely stateless and
therefore inherently thread-safe.  Therefore, there is no reason to
create a distinct instance for each appender.  Moreover, once created it
never needs to be modified, therefore it should be properly marked as
immutable via the final keyword.
marked SocketAppender convenience constructors as deprecated

Convenience constructors that are used to set mutable fields that have
proper accessors add little value, and they make it more complicated to
subclass.  Best practice is to use constructor arguments only to
initialize fields that are immutable or for which an accessor method
cannot be safely provided within the design constraints of the class.

The only use of these constructors by logback modules is in the
SocketMin class.  However, because these constructors were exposed as
API (public modifier) there is a chance that other code is using them,
therefore marking them as deprecated rather than removing them.
fixed deprecation warning for SocketAppender convenience constructor
marked SSLSocketAppender convenience constructors as deprecated

For consistency with SocketAppender.
removed unused SocketReceiver.createExecutorService
use "receiver" instead of "remote" in receiver diagnostic messages
marked SocketAppender convenience constructors in access as deprecated

For consistency with logback-core.
moved MockContext and MockExecutorService to ..core.net.mock
added missing doc comments to MockExecutorService
fixed references to MockContext in test classes
modified ContextBase to shut down executor service on reset
removed old SocketAppenderTest from classic and access

These test classes were really testing SocketAppenderBase not
SocketAppender, per se.  The new implementation of SocketAppenderBase is
significantly different and will require a new unit test suite.
improved SocketAppenderBase

SocketAppenderBase now uses SocketConnector for its (re-)connection
logic, and uses an asynchronous task to dispatch events to the remote
receiver.  A configurable queue is utilized to relay logging events from
the append method to the dispatch task.  When the queue length is zero
(the default), a SynchronousQueue is utilized, preserving the previous
appender behavior.  When the queue length is greater than zero, a
bounded queue is utilized, allowing the appender to efficiently drop
logging events when remote receiver (or network) cannot keep up with the
rate of logging events delivered to the appender.
modified concrete appenders to use appropriate constructors

Mutable fields in SocketAppenderBase were previously exposed as
protected fields and modified by constructors in concrete subclasses.
This commit improves encapsulation of the base class by exposing
protected constructors for subclasses to invoke rather than directly
exposing the fields.  These new constructors are marked as deprecated,
as the convenience constructors on the base classes (which are also
deprecated) are the sole reason for their existence.  A future release
should remove all but the no-arg constructor from the base class and
subclasses.
corrected typo and other bugs in imgaes
listen for connections