Change dynamic and max plugins to monitor only temperature sensors

[mgr01]

"Max" and "dynamic" sensor aren't working very well when monitoring sensors with different units (e.g. when you are watching fan and temp sensors at the same time). I think the best way to fix this is simply to ignore all non-temperature sensors (that includes other virtual).

[alexmurray]

Thanks - I was thinking the same thing during the development of these two plugins.