Added support for Java tests

* Added java-wrapper.sh to be able to run Java classes
* Removed traces from TestBuffer
* Added JAVA variable support in configure script
* Added run of Java tests

Testing: 100%
Closes: #101
Documented thread module

* Added documentation
* Made Thread structure opaque
* Updated library to use newly created accessors
* Added typedefs for threads initialization, finalization and run routines

Refs: #2, #66, #87
Testing: 100%
Running java tests according to HAVE_JAVA conditional

Closes: #101
Testing: 100%
Documented error module

* Added documentation to aio4c/error.h
* Added AM_MAINTAINER_MODE macro
* Fixed full path problem in documentation generation by Doxygen
* Did not made ErrorCode structure opaque as it is not needed

Refs: #2
Testing: 100%
Documented selector module

* Added documentation to selector module
* Made Selector and SelectionKey structures opaques
* Updated selector test to use getters instead of accessing directly the structure

Refs: #2, #66, #87
Testing: 100%
Added compilation of test client/server

* Improved Java test Client/Server
* Improved client.c in order to send goodbye on pending close
* Added build of test/benchmark, test/client and test/server in autotools
* Added those new binaries to gitignore

Closes: #1
Testing: 100%
Initialize connection on accept

 * Acceptor now changes connection state to initialize once it has accepted a new connection
 * server now handles init event

Closes: #105
Testing: 100%
Added pointer to JNIEnv pointer

* JNIEnv was not correctly passed to AttachCurrentThreadAsDaemon

Closes: #107
Testing: 100%
Updated stats modules after thread update

* Renamed thread handlers to be compatible with new interface
* Using ThreadStop to stop stat thread

Refs: #66,#87
Improved connection string description

* Now both socket ends will be resolved as soon as they are known:
  * on server accept
  * on client connection

Closes: #103
Testing: 100%
Taking lock after checking connection state

 * In order to avoid unexpected segfault, does not take connection's lock
 when checking if it is already in requested state change

Closes: #110
Testing: 100%
Avoid SIGPIPE when sending on already closed connection

 * Added MSG_NOSIGNAL flag to send syscall in order to avoid unexpected SIGPIPE

Closes: #108
Testing: 100%
Added various debug logging

 * Logging some information when:
   * data is received when a connection should be able to receive
   * a select operation failed
   * various select error cases when iterating over ready keys
 * Added debugging about event handling and queues

Closes: #109
Testing: 100%
Do not handle write interest when connection is closed

 * Everything is in title

Closes: #111
Testing: 100%
Freeing queue items before returning from run handler

 * To avoid memory leak, queue items are now freed before returning
 from writer and worker run handlers

Closes: #112
Testing: 100%
Updating thread state to running

 * Once thread is initialized, its state is now set to running

Closes: #113
Testing: 100%
JNI does not handle anymore free event

 * Indeed, as server and client already take care of handling free event,
 it does not need to be handled again in JNI interface
 * Cleaned up debug message in jni server handler

Refs: #104
Testing: 100%
Connection dos not handle write interest when not being able to write

 * In order to avoid outbound data events to be queued to writer,
 write interest will not be handled when write is no more possible on the connection
 * Instead, a warning is issued in logs

Refs: #104
Testing: 100%
Moved write interest after closing connection

 * When enabling write interest, there is a possibility that writer wakes
 up and sends data before the worker takes control to close the connection
 (thus updating closing() status that will allow the client to send 'goodbye')
 * This will avoid again having incorrect state leading to JVM segfault

Refs: #104
Testing: 100%
Improved debug to avoid unnecessary traces

 * Removed some selector debug
 * Added a trace in worker to allow seeing when it processes a task

Refs: #104
Testing: 100%