Update license year range to 2016
Update license year range to 2016

Rich-Harris/acorn,ternjs/acorn,ajaxorg/acorn,TimothyGu/acorn,MarcelGerber/acorn,mysticatea/acorn,ajaxorg/acorn,mysticatea/acorn,marijnh/acorn,mathiasbynens/acorn,mathiasbynens/acorn,marijnh/acorn,TimothyGu/acorn,TimothyGu/acorn,MarcelGerber/acorn,mysticatea/acorn,Rich-Harris/acorn,mathiasbynens/acorn,ajaxorg/acorn,MarcelGerber/acorn,marijnh/acorn,Rich-Harris/acorn,ternjs/acorn,ternjs/acorn