shared library for pkgconf

 pkgconf is an implementation of the pkg-config system, which helps to configure
 compiler and linker flags for development frameworks.
 .
 pkgconf is a replacement for pkg-config, providing additional functionality
 while also maintaining compatibility.
 .
 libpkgconf is a library which provides access to most of pkgconf's
 functionality, to allow other tooling such as compilers and IDEs to
 discover and use libraries configured by pkgconf.
 .
 This package ships a shared library for libpkgconf.