New version of the appender

Hi,
I made a lot of changes to the appender to make it more like logstash:
* Added Filters so you can parse the Message and extract more fields with them.
* If someone want new filter he just need to implement the interface and add his own filter in the configuration.
* Option to index in bulks instead of one by one. (you can configure the bulk size)
* Option to add custom  template which will be send to ElasticSearch when the appender is loading.

The appender is not fully ready but I thought you would like to have a look at my changes..
Have the freedom to decide whether to take my changes or not :-)

uriel.