server: make snapshotting on KVM non-blocking

[yadvr]

This references and uses an already fixed solution from
MissionCriticalCloud/cosmic#68 to make
snapshotting on KVM non-blocking.

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Enhancement (improves an existing feature and functionality)
• Cleanup (Code refactoring and cleanup, that may add test cases)

[yadvr]

@blueorangutan package

[blueorangutan]

@rhtyd a Jenkins job has been kicked to build packages. I'll keep you posted as I make progress.

[blueorangutan]

Packaging result: ✔centos6 ✔centos7 ✔debian. JID-2625

[yadvr]

@blueorangutan package

[blueorangutan]

@rhtyd a Jenkins job has been kicked to build packages. I'll keep you posted as I make progress.

[blueorangutan]

Packaging result: ✔centos6 ✔centos7 ✔debian. JID-2626

[yadvr]

@blueorangutan test

[blueorangutan]

@rhtyd a Trillian-Jenkins test job (centos7 mgmt + kvm-centos7) has been kicked to run smoke tests

[blueorangutan]

Trillian test result (tid-3417)
Environment: kvm-centos7 (x2), Advanced Networking with Mgmt server 7
Total time taken: 24373 seconds
Marvin logs: https://github.com/blueorangutan/acs-prs/releases/download/trillian/pr3209-t3417-kvm-centos7.zip
Intermittent failure detected: /marvin/tests/smoke/test_host_maintenance.py
Intermittent failure detected: /marvin/tests/smoke/test_hostha_kvm.py
Smoke tests completed. 69 look OK, 1 have error(s)
Only failed tests results shown below:

Test	Result	Time (s)	Test File
test_hostha_enable_ha_when_host_in_maintenance	Error	301.66	test_hostha_kvm.py

[wido]

LGTM