Add missing documentation for all the remaining hooks invoked directly by all the Commerce modules and ensure all hooks are represented in the various modules' implementations of hook_hook_info().

Issue #1240944 by rszrama: ensure product prices don't get calculated multiple times if hook_field_formatter_prepare_view() is called multiple times on the same data in a pageload.

Add an API function to calculate the total amount of price components and use that in the order controller for calculating the order total; also adds a display formatter for a price field presenting a table of its various components.