TODO

Error checking around correct number of arguments
Allow functions to take variable arguments where appropriate (e.g. lpush, etc)
There currenlty exists no concept of key expiry as redis has. Is this even wanted, needed?
Privatize some of the internal functions so they are not exposed to the public (done in the privatize branch)
Async version of the API so that new storage adapters could work on an async basis (e.g. AJAX posting to server storage)?
Allow SETs to store aribrary data-type values

Unimplemented Functions

Functions that are missing which might prove useful. All expiry-based functions are omitted since that is a larger question.

KEYS
- keys (mostly implemented, only returns "*" at the moment)
- move
- randomkey
- rename
- renamenx
- sort
STRINGS
- getbit
- getrange
- mget
- mset
- msetnx
- setbit
- setrange
HASHES
- all functions
LISTS
- blpop, brpop, brpoplpush (seem unnecessary as js is single-threaded?)
- linsert
SETS
- sdiff
- sdiffstore
- sinter
- sinterstore
- sunion
- sunionstore
SORTED SETS (ZSET)
- all functions