bmc improvements, move fd_solver to self-contained directory

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/tactic/fd_solver/pb2bv_solver.h

@@ -0,0 +1,29 @@
+/*++
+Copyright (c) 2016 Microsoft Corporation
+
+Module Name:
+
+    pb2bv_solver.h
+
+Abstract:
+
+    Pseudo-Boolean to bit-vector solver.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2016-10-23
+
+Notes:
+   
+--*/
+#ifndef PB2BV_SOLVER_H_
+#define PB2BV_SOLVER_H_
+
+#include "ast/ast.h"
+#include "util/params.h"
+
+class solver;
+
+solver * mk_pb2bv_solver(ast_manager & m, params_ref const & p, solver* s);
+
+#endif