Remove 'zone.' prefix and force Ctnr names to be lowercase & no spaces in migrations
Enforce validation, re-allow uppercase, alter ctnr.email_contact field
Systems are no longer unique
pep8
Removed unused try/except
Fixed creation/deletion of systems, reduced number of queries by caching dhcp options
Merge branch 'core_migration_fixes' of https://github.com/murrown/cyder into murrown-core_migration_fixes

Conflicts:
	cyder/migration/management/commands/dns_migrate.py
Added error catching for missing Ctnrs
Merge pull request #2 from church29/murrown-core_migration_fixes

Murrown core migration fixes
Merge pull request #142 from murrown/core_migration_fixes

Core migration fixes