Use PGTypes instead of Haskell types in columns
Newtypes section in tutorial
Make the tutorial query running section clearer by providing input types to the runQuery function.
Explicitly don't import anything from the Tutorial modules
FIXME about using a unique tag in column name
max and min aggregators
Aggregators in advanced tutorial
Merge branch 'master' into pgtypes
Merge branch 'master' into pgtypes
Get rid of ShowConstant which is no longer needed
Merge branch 'master' into pgtypes
Merge branch 'master' into pgtypes

Conflicts:
	Opaleye/Aggregate.hs
	Opaleye/Operators.hs
Merge branch 'master' into pgtypes
Merge branch 'master' into pgtypes

Conflicts:
	Opaleye/Internal/Sql.hs
	Opaleye/Operators.hs