Minor changes needed to make the 'mp3 import' sources build with MSVC

(MSVC project changes to follow...)

libs/ardour/ardour/mp3fileimportable.h

@@ -20,7 +20,6 @@
 #ifndef _ardour_mp3file_importable_source_h_
 #define _ardour_mp3file_importable_source_h_
 
-#include <boost/shared_ptr.hpp>
 #include "ardour/libardour_visibility.h"
 #include "ardour/types.h"
 #include "ardour/importable_source.h"

libs/ardour/mp3fileimportable.cc

@@ -33,9 +33,10 @@
 #include "pbd/error.h"
 #include "ardour/mp3fileimportable.h"
 
-using namespace ARDOUR;
 using namespace std;
 
+namespace ARDOUR {
+
 Mp3FileImportableSource::Mp3FileImportableSource (const string& path)
 	: _fd (-1)
 	, _map_addr (0)
@@ -235,3 +236,5 @@ Mp3FileImportableSource::read_unlocked (Sample* dst, samplepos_t start, samplecn
 	}
 	return dst_off;
 }
+
+}

msvc_extra_headers/immintrin.h.input

@@ -0,0 +1,4 @@
+/*
+** Emtpy file to prevent Win32 compiler from complaining that the
+** file doesn't exist.
+*/