Comment 0 for bug 1086504

Follow-up report to:
Bug #1015572 “[Patch] import "Microsoft Visio Diagram (*.vsd)" files (internal, based on libvisio)”

libvisio >= 0.22 supports additional MS Visio file formats, which use a different suffix. These need to be added to Inkscape (currently, trunk only knows about *.vsd files):
<https://plus.google.com/108382325637135111255/posts/EKzVQZMpEfS>
<https://plus.google.com/108911244660285152681/posts/X4BsWSxAq5h>
<http://libregraphicsworld.org/blog/entry/libreoffice-gets-visio-2013-support>
<http://article.gmane.org/gmane.comp.graphics.inkscape.devel/39473>

Known issue:
Which types of Visio files are supported depends on runtime version of libvisio. The current extension system doesn't allow to check based on the version of a dependency, and build time configure options would not help to detect which version of libvisio is available at runtime.

Patch used for testing new formats:
Attached patch simply adds several newer file formats without further checking.
Note: with this patch, import of such newer file formats will simply fail on systems which have older versions of libvisio installed, without providing further information to the user.

TODO:
1) Verify new filetypes (possibly remove some)
1) Verify details of added file types (extension, mimetype, filetypename and -tooltip)
2) If possible, implement a runtime version check of libvisio in 'src/extension/internal/vsd-input.cpp', to only enable formats supported by the currently installed version of libvisio.
3) Discuss further desktop integration:
- add Visio filetype for Linux desktops to inkscape.desktop{.in} (?)
- add Visio filetype for Windows and OS X packages (?)