[Feature Request] Allow pushing the menu off the screen

[catthou]

I understand disallowing the menu to extend off the screen unexpectedly, but when a user explicitly requests it, it could be desirable; I'd love my "start menu"-style jgmenu to be docked at the left side of the screen, but I can't select items at the screen edge while I have a border. I want to keep the border for all my menus, but to still be able to slide my mouse cursor up the left side of my screen to select entries; therefore, I'd like the option for margin_x and margin_y to accept negative values to 'nudge' the root menu's left border off the screen edge.

Currently I get this message when attempting:
warning: negative value not allowed; value='-2'; key='config.margin_x'

Alternatively, allow the border to be "behind" the entries so that if all padding is zero, putting the mouse cursor on the border still can select the menu entry in front of it.