script: add a slew of includes all around and drop includes from script.h

Lots of files ended up with indirect includes from script.h.

src/test/base58_tests.cpp

@@ -12,6 +12,7 @@
 #include "script/script.h"
 #include "uint256.h"
 #include "util.h"
+#include "utilstrencodings.h"
 
 #include <boost/foreach.hpp>
 #include <boost/test/unit_test.hpp>