Make field alias optional.
Merge pull request #142 from skydb/optional-alias

Make field alias optional.
Add non-aggregated export.
Merge pull request #143 from skydb/non-aggregated-selection

Add non-aggregated export.
Fix system variable bug.
Merge branch 'unstable' of https://github.com/skydb/sky into unstable
Fix histogram() and avg() tests.
Add distinct (count) to available aggregations.
Merge pull request #144 from matthelm/distinct

Add distinct (count) to available aggregations.
Change grammar to use count(DISTINCT).
Merge pull request #145 from skydb/count-distinct-grammar-fix

Change grammar to use count(DISTINCT).
Add finalize step to SelectionField type to help format map-reduce aggregation data
Merge pull request #146 from matthelm/finalize

Finalize
Set LUACMSGPACK_MAX_NESTING=32
Merge pull request #151 from skydb/fix-blank-group-by

Fix Nesting