Merge master branch and resolve conflicts

- Resolved conflict in src/test/memory.cpp: Accept const qualifier on catch
- Resolved conflict in src/util/mpz.h: Keep HEAD's 64-bit digit handling
- Resolved conflict in src/util/mpz.cpp: Combine ptr() method with fdiv fix
- Resolved conflict in src/util/mpz.cpp: Adapt hash function for 64-bit values

src/test/memory.cpp

@@ -39,11 +39,7 @@ static void hit_me(char const* wm) {
                 Z3_mk_bv_sort(ctx,i);      
                 
             }
-<<<<<<< HEAD
-            catch (std::bad_alloc&) {
-=======
             catch (const std::bad_alloc&) {
->>>>>>> origin/master
                 std::cout << "caught\n";
             }
         }