Improve handling of super() calls and their return value
Improve handling of super() calls and their return value

Closes #774

othree/tern,neoclide/tern,neoclide/tern,fileability/tern,marijnh/tern,MarcelGerber/tern,emacsmirror/tern,emacsmirror/tern,MarcelGerber/tern,emacsmirror/tern,fileability/tern,fileability/tern,ternjs/tern,MarcelGerber/tern,othree/tern,ternjs/tern,marijnh/tern,othree/tern,neoclide/tern,ternjs/tern,marijnh/tern