remove '#include <iostream>' from headers and from unneeded places

It's harmful to have iostream everywhere as it injects functions in the compiled files

src/muz/base/dl_boogie_proof.cpp

@@ -121,11 +121,11 @@ namespace datalog {
     }
     
     void boogie_proof::set_proof(proof* p) {
-        std::cout << "set proof\n";
+        //std::cout << "set proof\n";
         m_proof = p;
         proof_utils::push_instantiations_up(m_proof);
         mk_input_resolution(m_proof);
-        std::cout << "proof set\n";
+        //std::cout << "proof set\n";
     }
         
     void boogie_proof::set_model(model* m) {
@@ -201,7 +201,7 @@ namespace datalog {
         ptr_vector<proof> todo;
         todo.push_back(p);
         ast_mark visited;
-        std::cout << "get_subst\n" << mk_pp(p, m) << "\n";
+        //std::cout << "get_subst\n" << mk_pp(p, m) << "\n";
         while (!todo.empty()) {
             proof* p = todo.back();
             todo.pop_back();

src/muz/base/dl_context.cpp

@@ -17,6 +17,7 @@ Revision History:
 
 --*/
 
+#include<iostream>
 #include<sstream>
 #include<limits>
 #include "ast/arith_decl_plugin.h"

src/muz/base/dl_util.h

@@ -257,12 +257,14 @@ namespace datalog {
             }
             container[i-ofs] = container[i];
         }
+#if 0
         if (r_i != removed_col_cnt) {
             for (unsigned i = 0; i < removed_col_cnt; ++i) {
                 std::cout << removed_cols[i] << " ";
             }
             std::cout << " container size: " << n << "\n";
         }
+#endif
         SASSERT(r_i==removed_col_cnt);
         container.resize(n-removed_col_cnt);
     }