Option to pass some key presses in insert mode to editor widget
(replaces 'passnewline'). This allows to rename symbols in insert mode,
complete parenthesis blocks, expand comments etc.

Macro expansion and code-completion works with dot command.

Task-number:QTCREATORBUG-4828
Change-Id: I5ff43818d4f7f183cd6f4ed8cc3a4586469ab65d
Reviewed-by: hjk <hjk121@nokiamail.com>