bytevector: add ostream output with hexdump

There is a hexdump template in fs.  Move hexdump to its own header,
then ByteVector can use it too.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>

lib/bytevector.cc

@@ -1,6 +1,8 @@
 #include "crucible/bytevector.h"
 
 #include "crucible/error.h"
+#include "crucible/hexdump.h"
+#include "crucible/string.h"
 
 namespace crucible {
 	using namespace std;
@@ -144,4 +146,10 @@ namespace crucible {
 	{
 		return m_ptr.get();
 	}
+
+	ostream&
+	operator<<(ostream &os, const ByteVector &bv) {
+		hexdump(os, bv);
+		return os;
+	}
 }