Provide a backup backend using mysqldump

Many users prefer to us mysqldump to perform MySQL backups, but can't afford the performance penalty of running a backup on the main database server. The idea is to let mylvmbackup take care of that, by spawning a second mysqld instance that accesses the tables on the snapshot. Then mysqldump is executed, pointing it to the second MySQL instance. Once the dump has finished, the snapshot can be discarded. Ideally it should be possible to use alternatives to mysqldump as well, e.g. mysqlpdump (http://www.fr3nd.net/projects/mysqlpdump/) or mysql-parallel-dump (http://sourceforge.net/projects/maatkit)