A number of retailers and manufacturers have a gift for holiday shoppers: product packaging that will not result in lacerations and stab wounds. The companies, including Amazon.com, Sony, Microsoft and Best Buy, have begun to create alternatives to the infuriating plastic “clamshell�? packages and cruelly complex twist ties that make products like electronics and toys almost impossible for mere mortals to open without power tools. Impregnable packaging has incited such frustration among consumers that an industry term has been coined for it — “wrap rage.�? It has sent about 6,000 Americans each year to emergency rooms with injuries caused by trying to pry, stab and cut open their purchases, according to the Consumer Product Safety Commission.