Persistent key-value database with network interface (metapackage)

 Redis is a key-value database in a similar vein to memcache but the dataset
 is non-volatile. Redis additionally provides native support for atomically
 manipulating and querying data structures such as lists and sets.
 .
 The dataset is stored entirely in memory and periodically flushed to disk.
 .
 This package installs the main redis-server package.