Universal builds of gstreamer on macosx and osxvideosrc

[Dan Kegel]

Solved!  I was bitten by gst-run.  Evidently gstreamer binaries
come in two flavors, versioned and unversioned.
The unversioned one is just an alias for gst-run,
which then launches the right tool... without arch.
That's why "arch -i386 gst-inspect" was running the 64 bit
version.  Doing "arch -i386 gst-inspect-0.10" works as expected.

(Using lipo -remove to create a thin version of gst-inspect was what clued me
in... it failed with a message that google found in the source for gst-run.)

A bug like this was fixed once in gst-plugin-scanner:
https://bugzilla.gnome.org/show_bug.cgi?id=615357
Now I guess a similar fix needs to be applied to gst-run.
Happily, the workaround is simple, so this isn't urgent.

I filed https://bugzilla.gnome.org/show_bug.cgi?id=709125 for this.

Apologies for bothering the list prematurely!
- Dan