main/ncurses: fix automatic dependency due to symlinks

The -libs subpackage depended on ncurses-terminfo when it shouldn't because when moving $pkgdir/usr/lib also moved /usr/lib/terminfo which is a symlink to /usr/share/terminfo which is part of ncurses-terminfo and thus a dependency would be automatically added by the prepare_symlink() function from APKBUILD.

So make the libs() function grab only actual libraries by matching /usr/lib/.so. (this does not match libraries meant for -dev which would be *.so) so /usr/lib/terminfo isn't caught up.

Also make the terminfo() function move /usr/lib/terminfo to it.

In the meantime also do other cleanup like removing unnecessary 'cd "$builddir"' declarations and make libs() depend on the same pkgver-rpkgrel of the ncurses-terminfo-base.