Rename netlink.py to linux_netlink.py

This is to comply to a comment from @cznewt in
https://github.com/tcpcloud/salt-formula-heka/pull/24.

Remove Heka decoder tz handling

Use netlink collectd plugin instead of interface

This patch replaces the "interface" collectd plugin by the "netlink" one. The
"netlink" plugin provides the same metrics as "interface" but plus other
metrics such as the number of dropped packets.

Use same collectd df options as StackLight MOS

This is now handled by the Heka formula the same way for all the Heka sandbox
decoders. https://github.com/tcpcloud/salt-formula-heka/pull/20

Remove the log counter filter from meta/heka

This filter should be configured by the heka formula itself.

Sample alarms

Add timezone to syslog decoder config

Set "hostname" in the linux_hdd_errors|counters filters

Use the proper module directory

The stacklight module dir is /usr/share/lma_collector/common, not
/usr/share/lma_collector_modules. This fixes it.

Fix decoder name

Remove the alarm-related filters

This fixes the decoder name in meta/heka.yml.

This commit removes the alarm-related filter configuration from meta/heka.yml.
Alarms will be defined in a different way (still under discussion).

Global collectd update

Fix the multipath condition

Refactored multipath support

This reverts commit 6edb3a7a68.