Build with newer Boost. From Fedora.

Index: gr-digital/lib/costas_loop_cc_impl.cc
--- gr-digital/lib/costas_loop_cc_impl.cc.orig
+++ gr-digital/lib/costas_loop_cc_impl.cc
@@ -34,6 +34,8 @@
 namespace gr {
 namespace digital {
 
+using namespace boost::placeholders;
+
 costas_loop_cc::sptr costas_loop_cc::make(float loop_bw, int order, bool use_snr)
 {
     return gnuradio::get_initial_sptr(new costas_loop_cc_impl(loop_bw, order, use_snr));
