extended documentation to reflect new SocketAppender behaviour towards synchronous/asynchronous queueing

* made AbstrackSocketAppender not lose events when socket connections gets lost (now uses LinkedBlockingDeque)
* extracted aspects of deque creation and output stream creation to factories in order to improve testability
* ecapsulated automatic flushing of output stream into a separate class in order to make this functionality testable
* slightly refactored internal structure of AbstrackSocketAppender to improve maintainability

When Multiple FileAppenders attempt to write files to the same
nonexistent directory, concurrent threads could attempt to create
the directory at the same time, where only one succeeds, while
the others hit an IllegalStateException. This patch modifies
FileUtil.createMissingParentDirectories() to gracefully handle
existing directories (no exceptions thrown).

This patch also removes FileUtil.isParentDirectoryCreationRequired()
as this allows for race conditions between the existence-check and
the directory creation. Note that File.mkdirs() already performs
an existence-check.

Fixes LOGBACK-128

Fix for LOGBACK-732, make charset configurable in SyslogAppender

* Add setCharset()/getCharset() methods to SyslogAppenderBase
* Add blurb to news html page
* Unit test

This change change takes the conservative approach of preserving current
behavior when setCharset() is not called, using the platform default encoding.

Add git attributes - to fix line endings

Add suggested git attributes and associated files that were not in sync
already with expected line endings.

moved remaining resources to src/main/resources

logback-access & logback-examples resource files moved from source
packages to resources packages to comply with maven standards.

Added note for the move of the SQL scripts to src/main/resources
from Jeremy Landis (PR #197) (LOGBACK-948)

moved db appender scripts to src/main/resources

moved db appender scripts to src/main/resources (duplicate of #190 -
cleaner)

POM Modernization

- Corrected maven xsd
- Removed duplication in child poms (url, license, version, groupId)
- Removed commented out scala items
- Removed commented out jetty servlet api
- Removed excess spacing
- Note JavaSE-1.6 & 1.6 oracle docs
- Replaced examples use of antrun with maven-dependency-plugin
- Updated plugin versions
- Added plugins in parent pluginManagement
- Updated mockito & log4j
- Dropped old slf4j-api 1.5.10 - pom pulls latest
- Moved modelVersion to correct location
- Explicit groupId everywhere
- Use maven properties for jdk version used for compiler plugin
- Added generation of test source & javadoc jars
- Added lifecycle mapping filter for gmaven for users without m2e configuration.
- Moved maven bundle to plugin management

Allow specifying time zone in TimeBasedRollingPolicy's fileNamePattern

LOGBACK-611

This reverts commit 495929dc.

parent.relativePath was being set to the default value unnecessarily.

Added note for thread naming -- from Mikhail Mazursky (PR #187)

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