small fixes for ver 1.8 on Windows

I've attached a file that contains two small fixes for version 1.8 on 
Windows.

1)
include/cr_threads.h

On Windows, need to include "cr_bits.h" for the symbol CR_MAX_CONTEXTS.

2)
crutproxy/main.c

Shadowing problem where each "if" block tried to copy the variable msg 
into its own local copy with the same name.  The "if" block variables are 
now renamed to avoid uninitialized variable warnings / errors.

         Sincerely,
         Peter Djeu