Handle IOError exception if no /etc/os-release

On Synology DSM OS (Linux base), python throws an IOError when open does not find a file.
Previously only OSError was handled, now it handles both the OSError and IOError.
Merge pull request #457 from desbma/develop

Fix incorrect kernel thread detection with --hide-kernel-threads
Fix cyclic import

glances_globals -> glances_logs -> glances_processes -> glances_globals
Fix cyclic import (again)

glances_globals <-> glances_logging
Update NEWS and add Scrutinizer badge
Improve Python 3 compatibility
glances.conf: update
Correct check issue error in client/server mode (issue #459) + exit on check failed + correct another issue on Linux CPU SNMP
Curses interface OK
Correct pb if array stats are None
Replace tree char
Add Web interface for the RAID plugin
RAID plugin ok for beta testing
Merge branch 'feature/issue447' into develop
Correct issue on Windows SNMP client
Restructure folder. Add export father class. Refactor CSV export feature.
Add diskio and fs plugins to the CSV export module
Export module are manage like plugin. Rename --output-csv option to --export-csv
Export module are threaded
Finalize the export module refactoring