Remove dupe engine, state ptrs from RoseContext

Remove the RoseEngine and stream state pointers frose RoseContext, as
they are also present in core_info.

Unify stream state handing in Rose to always use a char * (we were often
a u8 * for no particularly good reason) and tidy up.

src/scratch.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -104,8 +104,6 @@ struct core_info {
 
 /** \brief Rose state information. */
 struct RoseContext {
-    const struct RoseEngine *t;
-    u8 *state; /**< base pointer to the full state */
     u8 mpv_inactive;
     u64a groups;
     u64a lit_offset_adjust; /**< offset to add to matches coming from hwlm */