Provided shared libraries not registering.

[Kimmo Paasiala]

This came up on graphics/gdal but there could be others. It looks like
pkg doesn't register provided shared libraries if the libraries lack
an SONAME in their dynamic section. Was this changed on pkg 1.6 or has
it always been like that? What it does now is that 'pkg check -d' will
complain about missing shared libraries that are present and
applications using those libraries work fine.

-Kimmo