loading data files into cqlsh before the container get's exposed

[emschimmel]

This is a feature I use to run initialisation scripts before the container is exposed.
If a folder names /data is mounted, it will execute cql, cql.gz and sh scripts in alphabetic order.
This way the container doesn't have to be started empty, but can be started as a fresh container with a defined keyspace and data.

[tianon]

Closing given #31 (comment):

Closing with a similar rationale to #94 -- the proper deployment of Cassandra is clustered, and is much more complicated to get right automatically. It is not recommended to use a standalone deployment, and I fear such a feature would encourage folks to do so (since it couldn't possibly work with a cluster properly and/or detect clustered operation). For folks that really want to go there, building something like that on top of the provided image shouldn't be too much work. 👍