Multiple OutputURIs for MongoS [comSysto] HADOOP-59

Hi,

I added the capability to add multiple output URIs. Now its possible to support more than one MongoS for the output. Round robin is used for distribution. The API is backwards compatible.

How to use it:

MongoConfigUtil.setOutputURI(conf,  "mongodb://mongos1/mydb.mycollection mongodb://mongos2/mydb.mycollection"); (String is splitted by StringUtils.split)

It is possible to use the old way to too: 
MongoConfigUtil.setOutputURI(conf,  "mongodb://mymongo/mydb.mycollection");

Unfortunately, we have to define the database and collection name twice due to the MongoURI Format.

Kind regards
Carsten Hufe
- comSysto -