DetailedType added in Utils
Type is replaced with TypeExtra in a minimal set of places
Initial environment added to ScalarExprRoot.
Simple tests work.
Concatenation "||" doesn't work because result type is "text".
precision and nullability supported for a moderate set of scalar functions
TypeExtra is supported for most of non-scalar expressions.
Inference of implicit cast for scalar expressions added.
ImplicitCast ctor added to ScalarExpr.
Issues to be solved:
  - expected type inference for arguments of functions;
  - inference of implicit cast for non-scalar expressions;
  - support for more complex non-scalar expressions (superaggregates, ...).
autorules.mk
Added support for new MsSQL datepart enums
Merge branch 'arnon'

Conflicts:
	hssqlppp/src/Database/HsSqlPpp/Internals/AstInternal.hs
Merge remote branch 'ghsqppp/master'

Conflicts:
	hssqlppp/src/Database/HsSqlPpp/Internals/AstInternal.hs