Backport Fix a few typos in scala.scalajs.js package object docs

(cherry picked from commit 6689fef40aa84062bcb37da652cca88f07e04404)
Backport Fix #1191: Reset caseaccessor flag on export forwarders

(cherry picked from commit 2310223109bf2c81c255c82b32b94ac435c9acb2)