Support mongoDb replica sets and local mongo _id

Use URIParser to create connections so that connections to either a
single mongo db or a replica set are supported. A replica set connection
is required in order to be able to keep inserting documents in the
replica set when the master fails over.

Add an option to automatically generate a mongo _id field using the
event timestamp when inserting a document.
Allow empty arrays as values in grammar
range filter
some doc changes
rough first draft of metaevent filter
checkpoint
working proof of concept
fixed tag adding
field_remove option in base filter + fields are arrays only if they have more than one value
s/min/max/ typo
filter based on field names too + any or all match logic
Create cipher.rb

Adding a new filter. Cipher goal is to provide on the fly event content encryption and decryption. Beware of CPU cost.
New filter plugin "Advisor"
some docs changes
Create s3.rb
logstash.sysv.redhat uses exit code on status check

Update logstash.sysv.redhat to use exit code on status check.
Advisor simple remake

I tried to render general code for all, but i am using it for hoc solution. I like it with pre-gok-grep events then push out in kibana for debug. The best combo is to send "advisor_first" via sns ( i put in the sns the kibana http, nice idea for fast 	
intervention like errors report ), and then "advisor_info" on sns yet after the "time_adv" for see more detail about the different error and the numbers.
Then if you want use my S3 outputs for store the result on bucket :)
Update s3.rb

I used it for a week and it works well. Try it if you want:)
Merge remote-tracking branch 'logstash/master' into improve-mongodb-output

Conflicts:
	lib/logstash/outputs/mongodb.rb
allow to specify the timezone to use in date filter