Version 1.16.0

• Add interp.New ... Execute API to speed up and reduce allocations when executing the same program multiple times. #100
• Add ExecuteContext API to support timeout and cancellation. #103
• Optimized string concatenation when concatenating more than two strings, for example x = "a" "," "b". #99
• Reduce allocations in a few other places, such as print, printf, sprintf(), and field parsing. #102
• Add proper Go 1.18 fuzzing support for fuzzing the AWK source and input. #103