Add refined types for individuals and other improvements 

This adds specific types for individuals, so each individual entity in Freebase gets a unique type. 

The type for individual X only has properties P where X.P actually returns interesting data, i.e. a non-empty sequence or a non-nullable valye. The types of properties for individuals are thereby adjusted to be "non-nullable", i.e. ```Individuals.Hydrogen.BoilingPoint``` has type ```float``` rather than ```Nullable<float>```.

This makes Individuals much more useful for exploring sparse data, as you can "dot" through an individual and see exactly what properties actually have interesting data.

The feature is on by default (which means this may be a breaking change) but can be turned off using ```UseRefinedTypes=false``` as a static parameter.

The checkin also adds 
* an Individuals10 view of individuals, which increases the number of items in the table by 10x
* likewise Individuals100
* likewise IndividualsAZ, which buckets the individuals by first character of name A-Z and includes 2x individuals in each bucket.

These are all techniques to increase the number of individuals that you can reasonably address.

This also adds ``--warnon:1182`` for unused variable warnings in FSharp.Data and FSharp.Data.DesignTime, and fixes a few of those warnings in Freebase code