Add posibility pass hash to ActiveReccord::Querying#order

Hi guys

I have added possibility pass hash to order method. Also i updated symbol parsing.

Here is the pull request - https://github.com/rails/rails/pull/7765

Can you please provide some feedback?

So the main idea is to convert symbol or hash into Arel::Nodes::Ordering instead of Arel::Nodes::SqlLiteral.

Arel::Nodes::Ordering object contain information about table - so we can, for example, change alias on the fly