updating gemspec for 0.4.6 release
updating gemspec for 0.4.6 release

tenderlove/yajl-ruby,sferik/yajl-ruby,sferik/yajl-ruby,brianmario/yajl-ruby,mrkn/yajl-ruby,tenderlove/yajl-ruby,sferik/yajl-ruby,brianmario/yajl-ruby,brianmario/yajl-ruby