BlackBox Component Builder

By convention, a mouse-right click on a graphical object under Windows shows a popup menu.
In BlackBox for Windows there is already a platform specific modifier that
indicates that the right mouse button has been pressed. This modifier is defined in
HostPorts.right. In order to be able to abstract from the platform specific
modifier it is proposed to add a new platform independent modifier as Controllers.popup for that purpose.
This avoids the import of HostPorts in modules such as DevDependencies and TextRulers.
Similarly, the Alt key is defined in HostPorts but not in Controllers. Since it is used in several modules,
mainly for drag and pick, it is proposed to add another modifier named Controllers.pick.
It is proposed that pick is triggered by both the Alt key and the mouse middle button.