Add initial implementation of script_source

[imotov]

What do you think about this solution for the external source problem? It basically allows users to replace source in the query using a script. The replaced source is then used for highlighting, in script fields, etc. Here is a small demo: https://gist.github.com/3040566

[asoqa]

i want a solution to integrate elasticsearch with hbase

[gelmajjouti]

What happened to this idea? Looks like it could be very useful to query an external database for source.