Allow opening multiple documents in tabs instead of new windows

[Uwe Jugel]

Feature request:

I often do scientific drawings and posters in Inkscape and often have to share snippets between docs.
Therefore, I often have more that one Inkscape window open, which is quite cumbersome.

1. Having tabs instead would be really great. I think this will improve multi document work flow a lot.
2. In addition I'd like to have the option "do not close window when last tab closes", as it is for example provided by Firefox.

Ubuntu 10.10 32bit
Inkscape 0.48.2 r9819

[su_v (suv-lp)]

Feature request 1:
Duplicate of
Bug #170257 "Tabbed document interface for multiple documents (TDI/MDI)"
<https://bugs.launchpad.net/inkscape/+bug/170257>

Feature request 2:
Duplicate of
Bug #open blank document on 'close' "open blank document on 'close'"
<https://bugs.launchpad.net/inkscape/+bug/170550>

Based on the bug summary, linking as duplicate to bug #170257.