Add option to show/hide proposal with ctrl+space shortcut

[Dufgui]

• if editor is focused and suggestion are displayed and esc => make suggestion disappear
• bug if close parenthesis before open parenthesis, they disapear => must be in red
• if editor suggestion is not displayed, hit controle space, make it appear again
• move inside editor with mouse, hide suggestion
• move out of current word with left and right remove suggestion
• up and down do not move inside text but inside suggestion and hightlight the current suggestion
• if suggestion is displayed and one si selected and enter is pressed, insert the current suggestion
• option disableSuggestionOverText controle this behaviour