hide (root) in layer list when there's a normal layer

[Buliabyak-users]

Mental, please try it and let's see if it breaks anything.

[Colin Marquardt (ubuntu-marquardt-home)]

I'd also suggest removing the following item from the
context menu:

#: ../src/interface.cpp:1284
msgid "Go to root"

See also
http://permalink.gmane.org/gmane.comp.graphics.inkscape.devel/9838

[Mental-users (mental-users)]

It turns out there's a really simple answer for this. Just
omit (root) from the selector unless it is the current
layer. I'll remove "Go to root" as well.

[Mental-users (mental-users)]

Done.

[Mental-users (mental-users)]

IMO, creating the first layer in a document that previously
had none should also move any root-level SPItems into the
newly created layer. Will track that in a separate bug.