Add a persistent connection for librato

When sending metrics and annotations to librato, use a persistent HTTP
connection.  clj-http.conn-mgr/make-reusable-conn-manager options can be passed
as a final map argument to librato-metrics to control the number of threads
used (default 4).
Use update-annotation
Query: Add support for regexp queries with ~=

This fixes #124.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Merge pull request #290 from algernon/f/query-regexp

Query: Add support for regexp queries with ~=
Load hipchat into riemann namespace

Fixes:
```
INFO [2013-12-10 17:36:26,647] main - riemann.bin - PID 81295

ERROR [2013-12-10 17:36:26,674] main - riemann.bin - Couldn't start java.lang.RuntimeException: Unable to resolve symbol: hipchat in this context, compiling:(etc/riemann.config:6:9)
```
Merge pull request #291 from digital-science/add_hipchat_to_config

Load hipchat into riemann namespace
riemann-pool: actually fire off futures to fill the pool.

This fixes :block-start true, which would never initialize the pool.
give the vm a bit more time
Merge pull request #293 from pyr/master

Give the vm a bit more time, helps openjdk6 not failing
avoid extra blank lines in logs
Allow a specifying different layouts

There are a bunch of things people might be interested in doing
wrt to riemann logging configuration. I tried to capture the most
common use cases, leaving more advanced configuration to people
willing to just drop in their log4j.properties file.

This code does not modify the existing behavior and thus will
not introduce inconsistencies for already configured riemann
instances.

It does add the following:

* ability to disable console logging
* ability to log to multiple files
* a choice of 3 layouts: the existing one (:riemann), :json-event(-v1)

The layout used for console output is specified with :console-layout
and defaults to :riemann, like today. Specifying a different layout here
can help people using runit to supervise riemann, since runnit expects
console logging.

The :json-event and :json-event-v1 layouts are useful for people shipping
riemann logs to logstash or elasticsearch and seems like a wide enough
standard (and a light enough dependency) to make the cut of riemann core
dependencies.
Merge pull request #295 from pyr/feature-json-event

More flexible logging configuration, JSONEvent support
flag /etc/default/riemann as conffile

... to avoid each upgrade from over-writing it.
install "default" file to correct location

... as referred to in initscript and where it belongs to by convention,
on redhat based systems.
Merge pull request #296 from mfournier/2-packaging-fixes

2 packaging fixes
config/async-queue!: docstring points to executor-service.
Test for (where (... event ...))
Merge branch 'master' of github.com:aphyr/riemann
riemann.time.controlled: Use of with-redefs to be slightly more forgiving.
Merge pull request #297 from udoprog/udoprog/with-redefs

riemann.time.controlled: Use of with-redefs to be slightly more forgiving.