#83 Attaching a tagged workspace to a frame makes things confused

[dima]

What should happen when one tags a workspace with the default bindings (via the
context menu) and then attaches this workspace somewhere else, also with the
default bindings (M-k a)?

Currently, if M-k a is pressed in a frame, this workspace is attached to that
frame, so you get an odd frame-inside-frame behavior

Things are then confused because actions become ambiguous. For instance if I
press the keyboard binding for next-tab, should this apply to an inner frame or
the outer frame?

I propose changing the code to make this impossible. Anybody see issues with this?