[WIP] dataframe example #17

[ocramz]

• add generics-sop dependency
• add Analyze.Values.Generic for generic conversion of record types into row types
• rename Value and ValueType constructors with shorter constructors
• rename Analyze.Common.Data typeclass to Key (since now the library uses Data.Data from base)
• add doctests
  • NB : some doctests rely on the current Show instance of some types (i.e. they will break if this changes).

-- in progress

• core : add list-of-hashmap frame types and API : Analyze.Frame.Sparse
  • dplyr-like API (groupBy, innerJoin, cumulative aggregates (scanl, scanr) ... )
• doctests
• row functions (e.g. add one column with the result of a function applied to one or more rows)
• generic decoding with optional types
  • e.g. foo = Foo Nothing 0.45 where data Foo = Foo { f1 :: Maybe Int, f2 :: Double} should decode as [("f2", VDouble 0.45)]
• core : decoding via logging-effect rather than throwing exceptions upon mismatching data.

[ocramz]

When the PR is ready, I will ask for one more review and when that is green I'll squash all these commits.

[ocramz]

Closing to avoid creep, will open distinct PRs