make it easier to add palettes

[hbons]

It would be very nice if there was an easier way to add palettes.
Right now you basically have to read documentation to be able to do it.

This can be made more discoverable by adding a "Add Palette..." entry in the palettes menu at the bottom.
Also, Inkscape could also allow a DnD of .gpl files into the canvas.

Doing either of these would copy the .gpl file to the hidden palettes folder and change the in use palette to the newly added one.

[su_v (suv-lp)]

Related reports:
Bug #171169 “export/import/edit/generate color palettes”:
<https://bugs.launchpad.net/inkscape/+bug/171169>

Bug #615163 “Auto-refresh palettes without restarting Inkscape”:
<https://bugs.launchpad.net/inkscape/+bug/615163>