fix FF contenteditable backspace bug.
https://github.com/yui/yui3/issues/1376
tweaks per YUI team advice on pull request.

https://github.com/yui/yui3/pull/1502
tweaks per YUI team advice on pull request.

https://github.com/yui/yui3/pull/1502
[History] : Remove `history-hash-ie`  from roll up.
tweaks per https://github.com/yui/yui3/pull/1502/files#r8857828
tweaks per https://github.com/yui/yui3/pull/1502/files#r8852815
Merge remote-tracking branch 'joecomotion/editor-para' into dev-master
[Editor] : Build.
[docs] Fix trailing comma in GH Contributors mocks
Merge branch 'dev-master' into dev-3.x
Merge branch 'app-history-fix' into dev-master
[YUI, Loader]: Build.
[docs] Fix trailing comma in XDR mocks
Merge branch 'dev-master' into dev-3.x
[test] Assert that next() bounds the function to the test
[test] Allow next() to define a context
[test] Make sure that next() preserves the original context