Augment fields at display time using a lookup file

[agirbal]

Often time we get data that is fairly cryptic e.g. codes that can easily be translated into human friendly strings. Ideally you could go to index setting, and assign a “lookup file” to a given field. From there the field will display the human friendly value. File could be just CSV with 2 columns, for example: http://gdeltproject.org/data/lookups/CAMEO.eventcodes.txt
This would be like a mini, in memory join, that'd be great for usability.

[rashidkpc]

#1543 would be used for this