Define parentBlockName in InsertLineBreak command.
vain stab at getting IE working
For InsertLineBreak command we need to make the same distinction for "isIE" as EnterKey.js did, which is that it's IE but less than version 11.
Get creative with the InsertLineBreak command, passing the current event when invoking it from EnterKey.js, so that the ctrl-key detection that previously lived in EnterKey.js continues to work as expected.
Quiet some jslint warnings.
For compatibility with IE make sure we require a w3 compatible range from selection.getRng()