Resolve Wrestrict warnings on GCC 8.1.1 (#51)

* Fix several misleading indentation warnings on GCC 8.1.1

* Fix reliance on undefined strcpy/sprintf behavior (-Wrestrict warnings)

The standard states that strcpy results in undefined behavior when the source
and destination buffers overlap. I resolved this with a combination of memmove
and strlen. Note that the resulting code is slightly less efficient.

Similarly, sprintf's behavior is undefined when copying takes place between
objects that overlap. I replaced most of these with a simple strcat, though
one required a temp buffer.

* Fix format in improved-edit.c to match surrounding code

src/act.informative.c

@@ -2593,7 +2593,7 @@ distance, int door)
     if (!*buf)
       sprintf(buf, "You see %s", GET_NAME(i));
     else
-      sprintf(buf, "%s%s", buf, GET_NAME(i));
+      strcat(buf, GET_NAME(i));
     if (--count > 1)
       strcat(buf, ", ");
     else if (count == 1)