Tighten up constructors

Since `setindex!` already can't broadcast vectors, removes broadcasting for arrays generally.

Changes instances of `Any` to `Type` where a type is expected (covers `DataType`, `UnionType`, `Constructor`, tuple types, but if I'm missing something).

Deprecates a couple constructors:
+ The long-marked `DataFrame(::Any..)`
+ `DataFrame(::Associative)`, which has permissive recycling, with the idea that the current `Dict` methods will cover `Associative`s