Reduce undo stack from two to one
Change recording undo timing after modifying text
Fix unintended range result while initializing on Firefox browser
We should not remove a latest element from listAncestor result
Prevent error in fromOffsetPath
Add emptyBookmark and fix bugs in history module
Fix wrong unit test
Update dist files
Merge with upstream develop branch
Add isBody function to determine BODY element in dom.js
Add comment for preventing unwanted default range on Firefox
Merge from upstream develop branch
Merge pull request #600 from HackerWins/feature/history-in-a-line

Feature/history in a line