Add function for snapshot creation and migration
Add PARAMETERS section for global parameters of the application
Add selector for snapshot based migration
Don't cache image file with fake cloud backend
Fix imports format in management module
Merge branch 'master' into snapshot-migration

Conflicts:
	pumphouse/management.py
Fix migration functions
Fix PEP8 issues
Add create_image function to Server class in fake Cloud back-end
Add default PARAMETERS
Fix snapshot repr for logging
Make wait_for not overwrite initial resource
Merge pull request #18 from MirantisLabs/snapshot-migration

Snapshot migration