[RFE] Split pane in same window for side-by-side proof reading/ translating of 2 different files

Hi, :-) In MS Office 2010, you can open 2 docs in the same window (each doc in a separate pane). When you scroll through the doc in one pane, the doc in the other pane scrolls an equivalent amount. This is called "proofreading mode". Could you please implement this for LibO? Having 2 docs open in separate windows (as you can at present) is not an equivalent functionality (you get duplication of toolbars, lose valuable screen real estate, etc.) Thanks if so. :-)