History: Mockup of a constrained translation GUI

When a user translates content from one language to another, the GUI should gently constrain him so that he is not tempted to write original new content while doing translation. This ends up screwing things up big time for the translation tracking infrastructure upon which the CLWE depends.

The attached Excel spreadsheet is a mockup of what this GUI might look like. Essentially, it constrains the user to only edit lines on the target language side, for which the corresponding line in the source language has changed.

Note that this assumes we can make a correspondance between lines in source and target language pages. Not clear how hard that is to do, but I think it should be feasible in most cases.