Adds a new rake task to import database dumps

These database dumps can be STDIN streams or from file.
Adds new capistrano task to export local data to remote

Like `cap alchemy:import[all,pictures,atachments,database]` you can now `cap alchemy:export[all,pictures,atachments,database]` to send local data to remote servers.
Escape the export db dump to be shell safe.
Merge pull request #649 from magiclabs/feature/export-database-to-remote

Feature/export database to remote