go_next_prev.lua with support of domain specific patterns through globals.go_next_prev

It's more convenient to have different next/previous patterns for different domains. For example, somewhere signs '>>' mean 'last' but sign '>' means 'next'. For google.com next page is «Next» and for google.by next page is «Следующая». Default pattern should not be extended to prevent following wrong «next» links. Thus usage of domain specific patterns for «next» or «previous» is good strategy.
Also this script ignores «www.» in the beginning of domain name.