Added hash store and changed values store to simple
Added _delvalue abstraction and HSET command
Fixed error handling (removed throw)

try/catch blocks do not work with asynchronous calls
Added rudimentary checking for correct amount of arguments
Added HEXISTS command and fixed HSET command
Added HGET command
Added HLEN command
Fixed rudimentary check for number of arguments
Added HCURSOR command
Fixed DEL command on edge cases
Added HDEL command
Added HGETALL command
added a little bit documentation of the HCURSOR command
added test case and documentation for the HDEL command
added documentation for the HEXISTS command
added documentation for the HGET command
added documentation for the HGETALL command
added documentation for the HLEN command
added test and documentation for the HSET command
 implemented HKEYS command