Merge pull request #171 from asergi/master

Drop obsolete code / Huge patch ! Thk for your work Alessio !!!
Correct a bug on the critical limit for procecess / Take into acount the number of core in the process CPU limits
On the road on the version 1.6.1
Repair unitest.py after commit https://github.com/asergi/glances/commit/d558e51e2a0f69928396a64c432eb6f255f15384
Workaround for unknown users.
Merge pull request #174 from jellonek/master

Support processes with uids unknown to pwd lib.