check if libpcap has PCAP_ERROR_IFACE_NOT_UP

This should prevent DNS plugin from being built on systems with libpcap
older than 1.0.0.

GitHub issue #373
RedHat RPM spec: updates for 5.4.0
curl_json plugin: avoid unlikely overrun

Signed-off-by: Florian Forster <octo@collectd.org>
curl_json plugin: avoid accessing off the end of the avl_tree_s

It's not written this way, but really we have a union { *key; *tree; }
which is differentiated by checking for the presence a magic field
which only exists in key.  This leads to accesses off the end of the
tree.  Putting the magic at start of the key avoids this.

Signed-off-by: Florian Forster <octo@collectd.org>
zfs_arc plugin: Collect "allocated" and "stolen" on FreeBSD only.

The appropriate log messages have been demoted to WARNING.

Github: #305
correct default write_graphite protocol in manpage
Merge remote-tracking branch 'origin/pr/409' into collectd-5.4
collectd.conf: Added example cgroups plugin config section.
collectd.conf: Added example df plugin ValuesAbsolute/Percentage options.
collectd.conf: Added an example write_riemann TTLFactor option.
switch default write_graphite protocol back to TCP

The *default* protocol was switched to UDP in 498a0dcd, when UDP support
was added to the plugin.

Switching this default back to TCP, because it makes the plugin break
for users upgrading to 5.4, and also because the UDP listener is disabled
in a default graphite installation (cf.
https://github.com/graphite-project/carbon/blob/0.9.x/conf/carbon.conf.example#L78)

Fixes GH#428
Display status of mic module
aquaero: Fix type names on aquaero plugin.

The percentage values are now reported as "percent" and the "flow"
type is included in the types.db list.
write_graphite: avoid printing out the NULL value in error messages
configure.in has been deprecated for a while now
Autoupdate
make build outputs more quiet

"make V=1" reverts the output to the usual verbosity level

Thanks to @jbergstroem for suggesting this !
Replace you with your in error message

Signed-off-by: Florian Forster <octo@collectd.org>
Avoid using first person in the error message

Signed-off-by: Florian Forster <octo@collectd.org>
Update collectd.conf.pod

spotted by lukas227 in IRC:
23:43 < lukas227> Hi, I think I found a mistake in the threshold.conf(5) man page: the example
                  THRESHOLD CONFIGURATION is within <Threshold></Threshold> tags, but should
                  probably be within <Plugin "threshold"></Plugin> tags (doesn work with
                  <Threshold> for me)
Day changed to 27 Sep 2013

Signed-off-by: Florian Forster <octo@collectd.org>