Set thread name

Reverted parent version from 1.2.0 to 1.1.3 for now.

ShutdownHook Configuration  Element

context via a shutdown hook. Enabled via the shutdownHook configuration
element (backed by the Joran ShutdownHookAction). 

Basic implementation provided, DelayingShutdownHook, stops the Logback
context after a specified delay (default is 0 for immediate shutdown).

Updated news page under revision 1.1.3 and added details to the
configuration manual page.

It is much easier to identify threads in thread dumps when they have meaningful names

Use ServiceLoader pattern to control logback bootstrap process

Configurable worker thread join timeout in AsyncAppenderBase

timeout instead of the default 1000ms. Added unit test to verify correct
function and updated appenders documentation describing new
configuration parameter and suggested uses. Added to news page under
release 1.1.3. 

Documentation, Unit Testing included.

Added a file to describe general guidelines for submitting pull requests.

Use an abstract method to create the SyslogOutputStream that subclasses can override