WARSAW‚ March 13 (Reuters) - Polish farmers increased the number of trucks they let through the Dorohusk border crossing with Ukraine on Wednesday but backpedalled on a promise to unblock it completely‚ state news agency PAP reported on Wednesday. Protest leader Wojciech Los told PAP that the number of trucks allowed to cross had been raised to five per hour from one or two previously. He had previously said that all trucks stuck there would be allowed through as a gesture of goodwill. "...