MonetDB: scripts for database initialisation.

create-monetdb.sh: creates "flywaydb" database, user and neccesary schemas.
destroy-monetdb.sh; stops database and destroys it.

tested on Kubuntu 14.04.
MonetDB: changed scripts, removed unnecessary files.
MonetDB: support for concurrent migrations.

Concurrent migration needs declaring MonetDBConcurrentLockManager as one
of callbacks in Flyway.