[PRD-999] move hosts_file class call in os_common
Merge pull request #582 from Mirantis/prd999

[PRD-999] move hosts_file class call in os_common
Fix hosts file creation class
Merge pull request #583 from monroid/fix_hosts

Fix hosts file creation class
[PRD-1871] fix race condition for nailyfacts
Merge pull request #586 from Mirantis/prd1871

[PRD-1871] fix race condition for nailyfacts
Merge branch 'master' into ubuntu-3.2-WIP