per-cpu statistings on Linux and cpu in % on Solaris

Hello,

This patch adds per cpu statistics on Linux (initial patch from Cyril Feraudet)

On Solaris, cpu statistics are converted to % because aggregation plugins do not like jiffies (initial patch from Cosmin Ioiart)

Note : Linux collects jiffies on values that seems to be %. So aggregation plugins should not complain. But one day, one should add an option to have % instead of jiffies on Linux too.

Regards,
Yves