integration work:

- use SWI flags whenever possible
  - support by module unknown, escapes, strings
  - accesss thread info fom SWI
  - allow strings to be input as strings.
  - remove some unused flags.

C/c_interface.c

@@ -3433,7 +3433,7 @@ YAP_SetCurrentModule(Term new)
 {
   CACHE_REGS
   Term omod = CurrentModule;
-  CurrentModule = new;
+  LOCAL_SourceModule = CurrentModule = new;
   return omod;
 }