Switch some build requirements to pkgconfig format
    
    Upstream uses PKG_CHECK_MODULES to build against libevent, tinfo,
    ncurses, and ncursesw.  Per the packaging guidelines, these build
    requirements should be expressed in the pkgconfig format, rather than by
    package name.
    
    https://docs.fedoraproject.org/en-US/packaging-guidelines/PkgConfigBuildRequires/