riemann plugin: Use the new strarray interface to allow indefinite number of tags.
ethstat plugin: Fix the map lookup.

Previously, a pointer into the configuration structure was used to look
up the mappings. Because the configuration structure is freed or
otherwise modified, this does not work as intended (and may actually
lead to a segmentation fault when unlucky).

For completeness sake, a shutdown callback was added to free the used
memory on exit.

Fixes Github issue 224.
riemann plugin: Implement the "StoreRates" option.
Merge remote-tracking branch 'github-octo/pyr/riemann' into pyr/riemann
Fixed a small typo in the ethstat plugin

Signed-off-by: Florian Forster <octo@collectd.org>
dbi plugin: Replace cdbi_config_set_string() with cf_util_get_string().
Merge branch 'collectd-4.10' into collectd-5.1
Merge branch 'collectd-5.1' into collectd-5.2
Merge branch 'collectd-5.2'
dbi plugin: Implement support for numeric options.

Fixes Github issue #233.
Look for IOPowerSources.h on Darwin only

Signed-off-by: Florian Forster <octo@collectd.org>
write_graphite: Decrease a buffer size.

If the buffer is too large, it is possible that the message cannot be
send using the send buffer, leading to a failed assertion in
wg_send_message().

Fixes Github issue #226. Thanks to @bwhaley for reporting this.
Merge remote-tracking branch 'origin/collectd-5.2' into collectd-5.2
riemann plugin: Clean up the riemann_connect() function.

Don't warn when connecting to some address fails. The system could, for
example, not have any IPv6 connectivity but the address record also
includes an IPv6 address. In this case a connect(2) call will fail but
this is not a problem.

Due to the new locking one of the concurrency checks was made redundant.
write_riemann plugin: Rename the "riemann" plugin.
write_riemann plugin: Ensure a unified logging prefix.
src/collectd.conf.in: Rename "riemann" to "write_riemann".
write_graphite: Use the complain mechanism to report connection errors.

Fixes Github issue #236. Thanks to @pyr for reporting it!
src/utils_complain.[ch]: Fix the complaint mechanism after the sub-second change.
write_graphite plugin: Remove two more redundant error messages.

The failing functions already print an error message; don't spam the logs
by duplicating this.

Further fixes Github issue #236.