Develop WMArchive QL to support queries in short and long term storage

[vkuznet]

To accommodate user queries we need uniform Query Language to be used in WMArchive regardless of the storage. If we'll use MongoDB short term storage it provides JSON based QL [1]. For HDFS we should leverage Hive [2] or others. If we'll use DAS-QL approach it can be adopted to [1] and [2].
Or, we can use different QLs based on back-end. It is open issue.

[1] https://docs.mongodb.org/v3.0/tutorial/query-documents/
[2] https://docs.treasuredata.com/articles/hive

[vkuznet]

done, see https://github.com/dmwm/WMArchive/wiki/WMArchive-queries