netapp plugin: Added support for SnapVault® statistics.

If enabled, the plugin collects lag time, transfer duration and transferred
bytes for each relationship. The interval at which those information is
collected may be configured.
netapp plugin: Added VFiler® support.

The plugin now accepts the <VFiler> config block (inside <Host> blocks). This
is treated similar to <Host> blocks (it accepts all the same config options)
and it inherits all connection related settings from the surrounding <Host>
block (which may, however, be overwritten inside the <VFiler> block). However,
all data collecting operations are done in the context of the specified
VFiler®.
netapp plugin: Added support for collecting dedup/compressed saved info.

This information is available from the SIS subsystem starting with OnTap 8.1.
netapp plugin: Added support for quota statistics.

If enabled, the plugin collects the used space and the number of used files
based on qtree quotas. The interval at which those information is collected
may be configured.
netapp plugin: Updated copyright information.
Merge remote-tracking branch 'github-tokkee/sh/netapp'