[WIP] - converting sigar -> AIX commands
implement network plugin for aix.
minor code style fix.
aix uptime lookup is similar to solaris one.
fix regex for interface info.
AIX plugin for filesystem
fix aix uptime.
Unit test for Aix plugin uptime.
Refactored Aix uptime unit tests.
Fixed few bugs while unit testing.
Added unit tests for AIX filesystem and network plugins along with a minor fix.
Added missing tests for netstat -nrf inet6.
ohai plugins hostname and platform specs.
Unit tests for cpu, kernel and platform plugins of AIX.
Fixed the uptime test-case that was failing in jenkins due to missing stubbing of DateTime.
Port AIX plugins to 6-stable
Merge pull request #207 from opscode/adamed-OC-9106-re-merge

OC-9106 AIX Ohai changes re-merge