added pexpire and pexpireAt methods for redis and mongo. Added emoticons for leveldb (as per existing implementation by @psychobunny LOL)

src/database/level/main.js

@@ -75,4 +75,12 @@ module.exports = function(db, module) {
 	module.expireAt = function(key, timestamp, callback) {
 		// <__<
 	};
+
+	module.pexpire = function(key, ms, callback) {
+		// o_o
+	};
+
+	module.pexpireAt = function(key, timestamp, callback) {
+		// d-_-b
+	};
 };

src/database/mongo/main.js

@@ -90,4 +90,12 @@ module.exports = function(db, module) {
 	module.expireAt = function(key, timestamp, callback) {
 		module.setObjectField(key, 'expireAt', new Date(timestamp * 1000), callback);
 	};
+
+	module.pexpire = function(key, ms, callback) {
+		module.expireAt(key, Date.now() + parseInt(ms, 10), callback);
+	};
+
+	module.pexpireAt = function(key, timestamp, callback) {
+		module.setObjectField(key, 'expireAt', new Date(timestamp), callback);
+	};
 };

src/database/redis/main.js

@@ -96,4 +96,12 @@ module.exports = function(redisClient, module) {
 	module.expireAt = function(key, timestamp, callback) {
 		redisClient.expireat(key, timestamp, callback);
 	};
+
+	module.pexpire = function(key, ms, callback) {
+		redisClient.pexpire(key, ms, callback);
+	};
+
+	module.expireAt = function(key, timestamp, callback) {
+		redisClient.pexpireat(key, timestamp, callback);
+	};
 };