SourceEditor::mouseMoveEvent() displays the translation on the fly
improved SourceEditor::modify_the_text_format() : the code has been factorized
Dipydoc version #30 : added 'rmode_textformat' tag
Merge branch 'feature35' into dev
The third reading mode ('read mode') has been defined, allowing to display the translation on the fly, when the mouse hovers over an extract. The UI has been updated and the Dipydoc's format slightly amended (version #30).