sys-cluster/hpx: Fixed file collision with sci-mathematics/spin

hpx with new version creates a file /usr/bin/spin which is reason of a conflict.
I've renamed a file into hpx_spin

Reported in bug 617486

Package-Manager: Portage-2.3.5, Repoman-2.3.2

sys-cluster/hpx/hpx-1.0.0.ebuild

@@ -76,6 +76,7 @@ src_test() {
 
 src_install() {
 	cmake-utils_src_install
+	mv "${D}/usr/bin/spin" "${D}/usr/bin/hpx_spin"
 	if use examples; then
 		insinto /usr/share/doc/${PF}
 		doins -r examples