Grok does create field when pattern matches all message

As of today grok filter does not create a specific field
if the grok matches the whole message. This commit changes
this behavior and make grok create the required field in
the configuration file
enhanced translate filter
some doc updates and typo fixes
blocking congestion check implementation for redis output
fix typo
don't check for congestion on teardown
LOGSTASH-978 - an input for the varnish shared memory binary log
Added HipChat output.
- Add a sleep filter
- Use Stud::Task to more easily manage any exceptions from the Agent
runner
- Add experimental ruby filter
- Add example parsing the graphite carbon text protocol
- exit nonzero on configuration errors; this also has the intentional
effect of not barfing a stack trace on config errors.
- improve validation reporting
- check to_f and to_i conversions with :number validation
- Graphite input! :)
- include all fields by default (include_fields being empty is default,
so we want all by default!)
- add 'replay' mode to the sleep filter. This enables replaying of
events on a scale of the original event timeline. You can change
the speed by setting 'time' to a multiplier (2 == 2x faster, 0.5 == half
as fast)
- log when we sleep
- add elasticsearch input. Uses the 'scroll' rest api to walk through
  a given query's results.
e Please enter the commit message for your changes. Lines starting
- note elasticsearch input