add rake tasks for mysql db backups/restores
postgresql db backups
add specs for backup task
whitespace fixes and other minor things
only sanitize_filename the actual filename
do not use the PGPASSFILE if no password is provided
db backup filename depends on db adapter
pg_dump needs the database name as the last param
Add /backup to .gitignore
Merge pull request #2079 from opf/feature/backup_task

Feature/backup task