write_riemann: Add extra meta strings as attributes in notifications
write_riemann plugin: Receive acknowledge message when using TCP.

Not receiving an acknowledge message when communicating with riemann over TCP
will cause the riemann instance to eventually hang for extended periods of time
because of resource exhaustion.

Took the time to reaorganize the riemann_send function to simplify locking.
Add support for a custom user agent at compile-time

Make it possible to specify a custom user agent at compile time
and then use on all libcurl calls instead of just going with
PACKAGE_NAME/PACKAGE_VERSION
Fix handling of 127.0.0.1 instead of localhost for *sql plugins

The mysql and postgresql plugins have special handling if you
use localhost as your hostname.  Sometimes you need to use 127.0.0.1
instead and want to not have that make changes to the hostname
for the metrics.
configure.in: Move the useragent config to a more appropriate block.
Merge pull request #425 from spotify/master

write_riemann plugin: Receive acknowledge message when using TCP.
Merge pull request #417 from udoprog/udoprog/riemann

write_riemann: Add extra meta strings as attributes in notifications
Append rules/targets to existing chain.

This patch allows appending rules/targets to an existing chain instead
of overwriting it. This way, it is possible to split filter chains
definition among several files.
Rewritten condition more clearly.
Add a JMXProvider Class Loader to be able to load Provider using
getConnectorAsService from JMXConnectorFactory. The protocol remoting-jmx
using by JBOSS > 7 need that to work.
Merge pull request #444 from falzm/master

Append rules/targets to existing chain.
dbi plugin: fix a warning mentioning snmp plugin
dbi plugin: register one read callback for each database block

By using a distinct read callback for each database block, collectd
will be able to query several databases in parallel. This is useful if
the plugin should handle many queries. This lets the user split them in
chunks and speed up the retrieval.
Merge pull request #452 from alexscott/master

Add a JMXProvider Class Loader to be able to load Provider using
Merge pull request #441 from katzj/localhost-sql

Fix handling of 127.0.0.1 instead of localhost for *sql plugins
Merge pull request #453 from vincentbernat/feature/parallel-dbi

Handle several databases in parallel with dbi plugin
Add support for custom attributes.
Add documentation bits for the new 'Attribute' directive
Ignore more build artifacts

This hides:

- vl_utils_lookup_test
- junk left behind by pod2man
- the buildperl dir
Merge pull request #459 from pyr/feature-riemann-attributes

Add support for custom attributes.