first working parts of prepared/graceful shutdowns
make sure that message processing is enabled on graceful shutdown
escape carriage returns in CSV output

fixes Graylog2/graylog2-web-interface#660
refucktored initializers to allow central partial shutdowns
no longer test jdk6 on travis
add multi metric request resource

for Graylog2/graylog2-web-interface#665
properly use rest listen address when binding

fixes #462
avoid running out of memory by not starting two new threads every second
mark open file limit notification as fixed

(as it gets really annoying when flashing the icon so often)
use natural ordering for index failures, set proper indices. fixes #468
improve JSON field type handling for GELF processing. fixes #438
yes it is. #bitteLassMich
Implementing a basic check for stream permissions for single messages

Fixes #464
Disabling check for open files limit if notification is already present

This prevents log spamming on the server and flickering of notifications
if the open file limit is too low on multiple hosts. This is not the
optional solution for it, because we need the ability in the Notification
class to check for a tuple of notification type and node, right now it
checks for the type only.
Implementing rule type to check for the presence (or absence) of fields

Fixes #418
don't log a line every time the checks detects the condition.

only log when the notification wasn't there before so we don't flood the log unnecessarily
also mention the threshold value in the log line
increase the level from info to warn because it really is a warning
cycling the deflector index could fail to update the index range for newly created index

if the deflector target index was empty it would get no corresponding index range assigned.
now for the deflector target graylog2 will always properly create an index range entry

fixes Graylog2/graylog2-web-interface#656
improve date converter: fixes timezone, set default year for parsed dates without year
lowercase/uppercase converters. #458
flexdate converter. #469