fixing issues opened in GitHub + Calling Tony's script.

Issues Fixed:
1. https://github.com/ZS/database-migration/issues/11
2. https://github.com/ZS/database-migration/issues/10
3. https://github.com/ZS/database-migration/issues/9

Calling Tony's
1. Calling Rollback-DatabaseChanges if the application is down and there
is exception while migration.
2. Calling Publish-NonCriticalDatabaseChanges after bringing the
application online since this will fix the logical names of data and log
files to be same as physical name.