Make it better to use URI from Jedis / JedisPool

* no need to provide password / DB index when user uses URI
* can provide timeout when user users URI
JedisURIHelper.getDBIndex() now returns 0 when db index is not provided
Merge branch 'make-it-better-to-use-URI' of https://github.com/HeartSaVioR/jedis into HeartSaVioR-make-it-better-to-use-URI