[arch-general] New PKGBUILD for libtorrent-rasterbar

[Jeff Horelick]

Quick thing to change that i just noticed. The libtorrent-rasterbar.so
version was bumped (from libtorrent-rasterbar.so.4 to
libtorrent-rasterbar.so.5) and that confuses at the very least Deluge and
possibly other clients as well that use the versioned library rather than
the plain .so. Perhaps add a symlink in the PKGBUILD to link
libtorrent-rasterbar.so.5 to libtorrent-rasterbar.so.4 or
libtorrent-rasterbar.so to libtorrent-rasterbar.so.4.