Make AVal purging reset maxWeight
Make AVal purging reset maxWeight

See http://discuss.codemirror.net/t/tern-issue-with-new-and-scoped/295

fileability/tern,fileability/tern,othree/tern,othree/tern,messfairy/tern,mcanthony/tern,cdosborn/tern,messfairy/tern,emallson/tern,marijnh/tern,anandthakker/tern,albertinad/tern,dorellang/tern,jgiles/tern,talyian/tern,fileability/tern,neoclide/tern,emacsmirror/tern,marijnh/tern,jgiles/tern,ternjs/tern,albertinad/tern,talyian/tern,marijnh/tern,adrianton3/tern,emallson/tern,MarcelGerber/tern,talyian/tern,emallson/tern,MarcelGerber/tern,albertinad/tern,messfairy/tern,jgiles/tern,adrianton3/tern,anandthakker/tern,emacsmirror/tern,adrianton3/tern,othree/tern,cdosborn/tern,neoclide/tern,ternjs/tern,neoclide/tern,MarcelGerber/tern,cdosborn/tern,anandthakker/tern,emacsmirror/tern,mcanthony/tern,dorellang/tern,ternjs/tern,dorellang/tern,mcanthony/tern