[master] fixed a build error on solaris/g++: apparently it has a conflict

definition of uint16_t in the boost namespace.  So avoid doing
'using namespace boost'.  Instead, import a specific name used in this file.
additional cleanups are made: be sure to include stdint.h just in case,
and remove unnecessary boost header file.

src/bin/resolver/resolver.cc

@@ -14,6 +14,7 @@
 
 #include <config.h>
 
+#include <stdint.h>
 #include <netinet/in.h>
 
 #include <algorithm>
@@ -21,7 +22,6 @@
 #include <cassert>
 
 #include <boost/shared_ptr.hpp>
-#include <boost/lexical_cast.hpp>
 #include <boost/foreach.hpp>
 
 #include <exceptions/exceptions.h>
@@ -57,7 +57,7 @@
 #include "resolver_log.h"
 
 using namespace std;
-using namespace boost;
+using boost::shared_ptr;
 
 using namespace isc;
 using namespace isc::util;