shairport-sync: Get rid of libc++ dependency

Two features which are not used by the package depend on a libc++.
Removing the proper entries in the Makefile allow compilation without a
libc++.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

sound/shairport-sync/patches/010-no-cxx.patch

@@ -0,0 +1,35 @@
+--- a/Makefile.am
++++ b/Makefile.am
+@@ -17,10 +17,6 @@ else
+ endif
+ endif
+ 
+-if USE_APPLE_ALAC
+-  shairport_sync_SOURCES += apple_alac.cpp
+-endif
+-
+ if USE_CUSTOMPIDDIR
+ AM_CFLAGS+= \
+ 	-DPIDDIR=\"$(CUSTOM_PID_DIR)\"
+@@ -66,11 +62,6 @@ if USE_PA
+ shairport_sync_SOURCES += audio_pa.c
+ endif
+ 
+-if USE_CONVOLUTION
+-shairport_sync_SOURCES += FFTConvolver/AudioFFT.cpp FFTConvolver/FFTConvolver.cpp FFTConvolver/Utilities.cpp FFTConvolver/convolver.cpp
+-AM_CXXFLAGS = -std=c++11
+-endif
+-
+ if USE_DNS_SD
+ shairport_sync_SOURCES += mdns_dns_sd.c
+ endif
+--- a/configure.ac
++++ b/configure.ac
+@@ -18,7 +18,6 @@ with_os=`echo ${with_os} | tr '[[:upper:]]' '[[:lower:]]' `
+ 
+ # Checks for programs.
+ AC_PROG_CC
+-AC_PROG_CXX
+ AC_PROG_INSTALL
+ 
+ PKG_PROG_PKG_CONFIG([0.9.0])