Add support for OpenVPN 2.3.0 status files.

Fix a bug that breaks this module if a server is running multiple instances of OpenVPN and one instance does not have any clients connected.
[perl_openvz] allow simulated plugins to be enabled and disabled
[perl_openvz] use hostname over veid
[perl_openvz] ignore lo interface. report like the real plugin does
[perl_openvz] fix update error
[perl_openvz] rework read_interface
make this a little more perly
typoed ref to hash; copy values
Merge pull request #1 from jyotty/cl/perl-openvz

Cl/perl openvz
[perl_openvz] fix missing semicolon from @jyotty
Add Alias and ConnectTimeout options to MySQL plugin
Drop st_mysql_options and use db->con->options instead
Add PluginInstanceFormat option to add plugin instance support
PUTNOTIF: Add the ability to populate meta options
Applying modifications as requested by octo from GitHub
[doc] Added documentation for adding of meta information using PUTNOTIF
Statsd: avoid doing a division by zero when calculating the average if we didn't get any values.
ReportByCpu and ValuesPercentage are now independant
ReportActive false now actually does as advertised

Change-Id: I93d9c36778253373c05b4efada5b082147656d89
Merge pull request #679 from ccin2p3/f/cpu-percent-vs-ticks

ReportByCpu and ValuesPercentage are now independant
Add final documentation for new libvirt plugin option PluginInstanceFormat