Remove 'using namespace std' from SerialTypes.h

This unfortunately cuases a ton of flow-down changes because a lot of other
code was depending on that definition existing. This has a fairly large chance
to break builds of external plugins, considering how many internal ones it broke.

src/file_analysis/Manager.cc

@@ -15,6 +15,7 @@
 #include <openssl/md5.h>
 
 using namespace file_analysis;
+using namespace std;
 
 TableVal* Manager::disabled = 0;
 TableType* Manager::tag_set_type = 0;