makeCache allows you to generate caching objects with timed expirey and LRU eviction.

Examples:

// Items can expire
var cache = makeCache();
cache.get('a'); // => undefined
cache.set('a', 1, {expireIn:1000});
cache.get('a'); // => 1
setTimeout(function(){
  cache.get('a'); // => undefined
}, 1100);

// Caches can be limited in size
// Least-recently-used items will evict automatically
var smallCache = makeCache({limit:2});
smallCache.set('a', 1);
smallCache.get('a'); // => 1
smallCache.set('b', 2);
smallCache.set('c', 3);
smallCache.get('a'); // => undefined