Schema changes in order to support both shlibs provided & required
Update libpkg API to access both shlibs_required and shlibs_provided.
Add the machinery to record the shlibs provided by a package
Add support for shlib providers to pkg-shlib
Avoid analysing symbolic links for shared library usage -- previous
code would analyse the file the sym-link pointed to.
Avoid trying to close a file descriptor that was never opened
Add support for displaying info about shared libs provided by packages
as well as those required by packages.
Add support for querying provided shared libraries to pkg query and
rquery

Fixes #306