Adding build status to README
Reducing code duplication due to server vs. radio

Created submodule graylog2-shared which is supposed to hold code which
is not part of the plugin api but still used by server and radio modules
Introducing MetricsHost and ProcessingHost interfaces
Moving several classes to shared module and refactor references,
       partially generifying those classes to use interfaces instead of
       Core/Radio objects
Refactoring the InputRegistry

Introducted abstract base class InputRegistry, each node type has to
subclass it.
Added callbacks (finishedLaunch, finishedTerminating) that are called
after launching/terminating an input.
Minor fix to input launch error reporting
Fixing some merge issues, bumping version number, correcting error
Bumping all version numbers to the SNAPSHOT of the next one
Adding first steps of DI to replace omnipresent Core object someday

Still WIP, currently the MetricRegistry and MongoConnection is injected,
      more to come.
Injecting MongoConnection & MongoBridge in Core object
close TCP connections properly on exception. #415
version check. fixes #295
fix sha256 in versioncheck. #295
update drools example file
return generic error for search exceptions

don't let the web interface think everything is alright, instead fill out the generic error object.
set upper range for relative timerange filters to avoid showing messages from the future. lol timezones :v
lower log level for stream rule exception

add exception tracking metric, not exposed in the ui (only via the "show metrics" menu item).

issue #357
clean up default log4j.xml

include log4j-extras to support better rolling file appenders, including size limits

fixes #357
search result chart widget. Graylog2/graylog2-web-interface#487
bump to rc.2
Propagating actual errors occuring during email transport
add http proxy for use with external resources

useful for setups where the individual graylog2 nodes don't have direct internet access
(e.g. to access http json path or do versionchecks)

fixes #422