Fixing uc_price(), css problems with a side effect of solving VAT problem

Problem

1. Using uc_vat, uc_quotes and uc_catalog at the same time will result displaying inconsistent prices on product node and catalog.
If the admin selects that the prices entered with VAT included they are showed without VAT on catalog pages.

2. The default catalog grid falls apart looks like css is not working.

The rootcause

1. Ubercart using uc_price() to alter price upon rendering. That requires to use the proper context before the call.
2. Class name separator in the catalog module is dash "-" not underscore "_"

This patch properly fixing these issues.

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Other things to be considered for future releases

This module defines functions that are already defined in uc_catalog.module I think there should be some sort of mechanism not to define function two times with the same name and functionality. Catalog module not core, but distributed with UC by default so that should be considered in the first place.