Merge tag 'v2.1' into develop

Glances version 2.1 release
Ready to start the 2.1.1 release !
Correct PsUtil issue on proc.memory_maps() - Issue #413
Automaticaly compute top processes number for the current screen - issue #408
Add try/except for NoSuchProcess error - issue #421
Change HTTPlib name for Python 3.4 - issue #419
Correct issue on Mac OS X running in non root (issue #423)
Another patch for non root user on Mac OS X - issue #423
Another patch bis for non root user on Mac OS X - issue #423
version 2.1.1
Merge branch 'release/v2.1.1'